Biomedical subjects

N Srinivasan

Publications and source records attributed to N Srinivasan.

At least 19 recordsLinked to original sources

PubMed2006

Cascade PSI-BLAST web server: a remote homology search tool for relating protein domains.

Owing to high evolutionary divergence, it is not always possible to identify distantly related protein domains by sequence search techniques. Intermediate sequences possess sequence features of more than one protein and facilitate detection of remotely related proteins. We have demonstrated recently the employment of Cascade PSI-BLAST where we perform PSI-BLAST for many 'generations', initiating searches from new homologues as well. Such a rigorous propagation through generations of PSI-BLAST employs effectively the role of intermediates in detecting distant similarities between proteins. This approach has been tested on a large number of folds and its performance in detecting superfamily level relationships is approximately 35% better than simple PSI-BLAST searches. We present a web server for this search method that permits users to perform Cascade PSI-BLAST searches against the Pfam, SCOP and SwissProt databases. The URL for this server is http://crick.mbu.iisc.ernet.in/~CASCADE/CascadeBlast.html.

Internet↗

PubMed2006

Protein Block Expert (PBE): a web-based protein structure analysis server using a structural alphabet.

Encoding protein 3D structures into 1D string using short structural prototypes or structural alphabets opens a new front for structure comparison and analysis. Using the well-documented 16 motifs of Protein Blocks (PBs) as structural alphabet, we have developed a methodology to compare protein structures that are encoded as sequences of PBs by aligning them using dynamic programming which uses a substitution matrix for PBs. This methodology is implemented in the applications available in Protein Block Expert (PBE) server. PBE addresses common issues in the field of protein structure analysis such as comparison of proteins structures and identification of protein structures in structural databanks that resemble a given structure. PBE-T provides facility to transform any PDB file into sequences of PBs. PBE-ALIGNc performs comparison of two protein structures based on the alignment of their corresponding PB sequences. PBE-ALIGNm is a facility for mining SCOP database for similar structures based on the alignment of PBs. Besides, PBE provides an interface to a database (PBE-SAdb) of preprocessed PB sequences from SCOP culled at 95% and of all-against-all pairwise PB alignments at family and superfamily levels. PBE server is freely available at http://bioinformatics.univ-reunion.fr/PBE/.

Amino Acid Motifs↗

PubMed2006

HARMONY: a server for the assessment of protein structures.

Protein structure validation is an important step in computational modeling and structure determination. Stereochemical assessment of protein structures examine internal parameters such as bond lengths and Ramachandran (varphi,psi) angles. Gross structure prediction methods such as inverse folding procedure and structure determination especially at low resolution can sometimes give rise to models that are incorrect due to assignment of misfolds or mistracing of electron density maps. Such errors are not reflected as strain in internal parameters. HARMONY is a procedure that examines the compatibility between the sequence and the structure of a protein by assigning scores to individual residues and their amino acid exchange patterns after considering their local environments. Local environments are described by the backbone conformation, solvent accessibility and hydrogen bonding patterns. We are now providing HARMONY through a web server such that users can submit their protein structure files and, if required, the alignment of homologous sequences. Scores are mapped on the structure for subsequent examination that is useful to also recognize regions of possible local errors in protein structures. HARMONY server is located at http://caps.ncbs.res.in/harmony/

Algorithms↗

PubMed2006

Genome-wide comparative analyses of domain organisation of repertoires of protein kinases of Arabidopsis thaliana and Oryza sativa.

A comparative analysis on protein kinases encoded in the completely sequenced genomes of two plant species, namely Arabidopsis thaliana and Oryza sativa spp japonica cv. Nipponbare is reported in the current study. We have analysed 836 and 1386 kinases identified from A. thaliana and the O. sativa genomes respectively. Their classification into known subfamilies reveals selective expansions of the plant receptor kinase subfamily comprising of Ser/Thr receptor kinases. The presence of calcium dependent kinases, and potential absence of cyclic nucleotide-dependent protein kinase of the type found in other (non-plant) eukaryotes, are other notable features of the two plant kinomes described here. An analysis on domain organisation of each of the protein kinases encoded in the plant genome has been carried out. Uncommon composition of functional domains like nuclear translocation factor domain, redox sensor domain (PAS), ACT and lectin domains are observed in few protein kinases shared between the two plant species. Biochemical functions characteristic of the domains recruited in these protein kinase gene products suggest their mode of regulation by alternate cellular localisation, oxidation potential, amino acid flux and binding of carbohydrates. Occurrence of multi-functional kinases with diverse enzymatic modules, such as Transposases and peptidases, tethered to the kinase catalytic domain is another interesting feature of the protein kinase complement of the O. sativa genome. Co-occurrence of diverse nucleotide and carbohydrate binding domains with catalytic kinase domain containing gene products has also been observed. Putative homologues of protein kinases of A. thaliana that regulate plant-specific physiological processes like ethylene hormone response, somatic embryogenesis and pathogen defence have been identified in O. sativa genome as well.

Arabidopsis↗

PubMed2006

Effect of ethanol on human osteosarcoma cell proliferation, differentiation and mineralization.

The habitual consumption of even moderate quantities of alcoholic beverages is clearly associated with reduced bone mass, increased prevalence of skeletal fracture and also it is the major risk factor for the development of secondary osteoporosis. The present in vitro study was designed to determine the dose response effects of ethanol on osteoblast-like human osteosarcoma cells (SaOS-2) proliferation, differentiation, mineralization and cyto-toxicity. SaOS-2 cells were plated in 48 and 6 well culture plates and exposed to different concentrations of ethanol (1, 10, 100, 200 and 300 mM) for 24, 48 and 72 h. At the end of incubation, proliferation of cells was studied using crystal violet Bioassay. The cell lysate was utilized to determine ALP activity and conditioned media were used to measure LDH activity. Histochemical localization of ALP and mineralized nodules were studied from cells treated with ethanol (10 and 100 mM) for 21 days. At higher doses, there was a significant reduction in cell number, whereas at lower doses there were variable effects. In 24 h treatment, the higher doses showed a significant increase in ALP activity, whereas 48 and 72 h treatments showed an opposite trend. Ethanol treatment caused a dose- and time-dependent increase in LDH activity. Ethanol treatment altered the quality of mineralization at 10 mM dose whereas completely inhibited mineralization at 100 mM dose, despite the presence of serum. In conclusion, the toxic effect of ethanol is reflected on cell proliferation, differentiation and mineralization even at low doses and at extended treatment duration.

Alkaline Phosphatase↗

PubMed2006

Influence of estradiol on mammary tumor collagen solubility in DMBA-induced rat mammary tumors.

Estradiol plays a vital role in the growth and development of mammary glands. It is a potent stimulator of metabolic processes in normal and carcinoma breast. A critical factor in determining mammary glandular morphology is the stroma. Collagen is a predominant component of the extracellular matrix and cell-collagen interactions are essential carcinogenesis. The present investigation explored the influence of estradiol on collagen solubility and metabolism in mammary tumors during tumor progression and regression. A single injection of 20 mg of 9,10-dimethyl-1,2-benzanthracene was given to rats at 7 weeks of age. With the appearance of the first palpable mammary tumor, the rats were treated with 0.5 microg estradiol or 50 microg tamoxifen daily for 30 days. The rats were sacrificed 24 h after 30 days of treatment. Estradiol appears to stimulate the synthesis of new collagens and thus contributes to the enlargement of the mammary tumors. This might have created a potential microenvironment by increasing the synthesis of suitable matrix that sustains the growth of the mammary tumors. In short, the present findings emphasize a definite mediatory role for collagen in estradiol promoted mammary tumor growth.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2006

MulPSSM: a database of multiple position-specific scoring matrices of protein domain families.

Representation of multiple sequence alignments of protein families in terms of position-specific scoring matrices (PSSMs) is commonly used in the detection of remote homologues. A PSSM is generated with respect to one of the sequences involved in the multiple sequence alignment as a reference. We have shown recently that the use of multiple PSSMs corresponding to an alignment, with several sequences in the family used as reference, improves the sensitivity of the remote homology detection dramatically. MulPSSM contains PSSMs for a large number of sequence and structural families of protein domains with multiple PSSMs for every family. The approach involves use of a clustering algorithm to identify most distinct sequences corresponding to a family. With each one of the distinct sequences as reference, multiple PSSMs have been generated. The current release of MulPSSM contains approximately 33,000 and approximately 38,000 PSSMs corresponding to 7868 sequence and 2625 structural families. A RPS_BLAST interface allows sequence search against PSSMs of sequence or structural families or both. An analysis interface allows display and convenient navigation of alignments and domain hits. MulPSSM can be accessed at http://crick.mbu.iisc.ernet.in/~mulpssm.

Databases, Protein↗

PubMed2006

A spectroscopic study of the interaction of isoflavones with human serum albumin.

Genistein and daidzein, the major isoflavones present in soybeans, possess a wide spectrum of physiological and pharmacological functions. The binding of genistein to human serum albumin (HSA) has been investigated by equilibrium dialysis, fluorescence measurements, CD and molecular visualization. One mole of genistein is bound per mole of HSA with a binding constant of 1.5 +/- 0.2 x 10(5) m(-1). Binding of genistein to HSA precludes the attachment of daidzein. The ability of HSA to bind genistein is found to be lost when the tryptophan residue of albumin is modified with N-bromosuccinimide. At 27 degrees C (pH 7.4), van't Hoff's enthalpy, entropy and free energy changes that accompany the binding are found to be -13.16 kcal x mol(-1), -21 cal x mol(-1) K(-1) and -6.86 kcal x mol(-1), respectively. Temperature and ionic strength dependence and competitive binding measurements of genistein with HSA in the presence of fatty acids and 8-anilino-1-naphthalene sulfonic acid have suggested the involvement of both hydrophobic and ionic interactions in the genistein-HSA binding. Binding measurements of genistein with BSA and HSA, and those in the presence of warfarin and 2,3,5-tri-iodobenzoic acid and Förster energy transfer measurements have been used for deducing the binding pocket on HSA. Fluorescence anisotropy measurements of daidzein bound and then displaced with warfarin, 2,3,5-tri-iodobenzoic acid or diazepam confirm the binding of daidzein and genistein to subdomain IIA of HSA. The ability of HSA to form ternery complexes with other neutral molecules such as warfarin, which also binds within the subdomain IIA pocket, increases our understanding of the binding dynamics of exogenous drugs to HSA.

Anilino Naphthalenesulfonates↗

PubMed2006

Effects of glucose and its modulation by insulin and estradiol on BMSC differentiation into osteoblastic lineages.

It is well known that diabetes affects bone in human and animal models, and leads to osteopenia and osteoporosis. Bone-mineral density and other biochemical markers of bone turnover are very much affected in people with diabetes. Reduced bone mass, occurring with increased frequency in diabetes mellitus, has been attributed to poor glycemic control, but the pathogenic mechanisms remain unknown. High concentrations of glucose (hyperglycemia) in diabetics leads to this complication. Very few in vitro studies using bone-cell lines have been carried out to address this problem. In this study, we examined the effects of different doses of glucose concentration (5.5, 16.5, and 49.4 mmol/L), alone, with insulin (0.6 microg/mL), or with 17beta-estradiol (E2) (10 nmol/L), on rat bone-marrow stromal cells (BMSCs) in the presence of an osteogenic medium. BMSC proliferation and alkaline phosphatase (ALP) were studied after 3 and 7 d of culture, respectively; the area stained for collagen and mineralized nodules was studied after 28 d of culture. With high concentrations of glucose, BMSC proliferation, ALP activity, the number of nodules formed, and the area stained for collagen were greatly reduced. Insulin treatment alone was able to increase [3H]-thymidine uptake or ALP activity, whereas both insulin and estradiol were able to increase the number of mineralized nodules and the area stained for collagen and mineralization. In conclusion, this study suggests that insulin and estradiol are able to contain the deleterious effect of high concentrations of glucose on BMSC-derived osteoblast proliferation and function.

Alkaline Phosphatase↗

PubMed2006

Effects of streptozotocin-induced diabetes mellitus on some bone turnover markers in the vertebrae of ovary-intact and ovariectomized adult rats.

Diabetes mellitus and estrogen deficit are known causes of osteopenia in animal models as well as in humans. In the present work, the combined effect of ovariectomy and diabetes was investigated. Diabetes was induced in ovary-intact and ovariectomized female Wistar rats with a single injection (50 mg/kg body weight, i.p.) of streptozotocin. The rats were administered insulin (I) daily or 17-beta estradiol (E2) on alternate days for a period of 35 days and sacrificed. Serum calcium (Ca2+), phosphorus (P), alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP), vertebral ALP, collagen, and glycosaminoglycans were estimated. The levels of serum Ca2+ and P increased in diabetic rats, but decreased after I or E2 treatments. Serum ALP and TRAP activity increased in the ovary-intact and ovariectomized diabetic rats. Vertebral ALP activity increased in ovariectomized diabetic rats, but decreased in diabetic rats, which were treated with I or E2. In the vertebrae, TRAP activity was elevated as a result of diabetes, but this was prevented by insulin or estradiol. Diabetes induced a decrease in total collagen in the vertebrae, while I or E2 treatment induced an increase. The levels of chondroitin sulphate and heparan sulphate decreased significantly in the vertebrae of both ovary-intact and ovariectomized diabetic rats, while hyaluronic acid increased. In conclusion, diabetes and ovariectomy each seem to affect the process of matrix formation and mineralization in the bone, and this is aggravated by the combination of diabetes and ovariectomy. The effects of I and E2 were similar, and both hormones reversed the changes brought about by diabetes.

Acid Phosphatase↗

PubMed2006

Effect of chromium on vertebrae, femur and calvaria of adult male rats.

Alloys of chromium have a long history of success in the surgical treatment of many orthopaedic defects. Nonetheless, prostheses loosening are commonly found around arthoplasties due to corrosion of metals. On this basis, it is hypothesized that chromium accumulation interferes with remodeling of bone. The present study aims to analyse the toxic effects of chromium on bone phosphatases in various regions of the bone in rats. Rats were treated with chromium intraperitoneally (0.5 mg/kg) in the form of potassium dichromate for 5 days. The accumulation of chromium is approximately 5.2-fold in the vertebrae, 8.9-fold in the femur and 8.7-fold in the calvaria, when compared to control. Chromium administration significantly reduced the activity of enzymes, eg, alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). The study revealed a significant increase in the concentration of calcium, altered bone formation rate and bone morphology in the femur, vertebrae and calvaria. The interesting findings of the current study suggest altered bone turnover.

Animals↗

PubMed2005

Antioxidant effect of ascorbic acid on PCB (Aroclor 1254) induced oxidative stress in hypothalamus of albino rats.

BACKGROUND: PCBs are one of the environmental toxicants and neurotoxic compounds which induce the production of free radicals leading to oxidative stress. Vitamin C is well known as an outstanding antioxidant. We determined the protective role of ascorbate on hypothalamic antioxidant system of Aroclor 1254 exposed rats. METHODS: The rats were injected Aroclor 1254 at a dose of 2 mg/kg bw/day intraperitoneally for 30 days. One group of rats received vitamin C (100 mg/kg bw/day) orally simultaneously with Aroclor 1254 for 30 days. Twenty-four hours after last treatment, the animals were killed and hypothalamic region was separated from brain tissue. Enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and vitamin C were estimated. Hydrogen peroxide (H(2)O(2)), lipid peroxidation (LPO) and acetylcholine esterase (AchE) activity were determined. Serum gonadotropins such as luteinizing hormone (LH) and follicle stimulating hormone (FSH) were also assayed. RESULTS: Activities of SOD, CAT, GPx, GR, AchE and the concentration of vitamin C were decreased while an increase in H(2)O(2) and LPO were observed in hypothalamus of PCB treated animals. LH and FSH concentrations were also decreased in serum of PCB exposed animals. Vitamin C administration retrieved all the parameters significantly except serum hormonal profiles. CONCLUSION: PCB induces oxidative stress in hypothalamus by decreasing the activities of antioxidant enzymes, which can be protected by vitamin C treatment.

Acetylcholinesterase↗

PubMed2005

Diversity in domain architectures of Ser/Thr kinases and their homologues in prokaryotes.

BACKGROUND: Ser/Thr/Tyr kinases (STYKs) commonly found in eukaryotes have been recently reported in many bacterial species. Recent studies elucidating their cellular functions have established their roles in bacterial growth and development. However functions of a large number of bacterial STYKs still remain elusive. The organisation of domains in a large dataset of bacterial STYKs has been investigated here in order to recognise variety in domain combinations which determine functions of bacterial STYKs. RESULTS: Using sensitive sequence and profile search methods, domain organisation of over 600 STYKs from 125 prokaryotic genomes have been examined. Kinase catalytic domains of STYKs tethered to a wide range of enzymatic domains such as phosphatases, HSP70, peptidyl prolyl isomerases, pectin esterases and glycoproteases have been identified. Such distinct preferences for domain combinations are not known to be present in either the Histidine kinase or the eukaryotic STYK families. Domain organisation of STYKs specific to certain groups of bacteria has also been noted in the current anlaysis. For example, Hydrophobin like domains in Mycobacterial STYK and penicillin binding domains in few STYKs of Gram-positive organisms and FHA domains in cyanobacterial STYKs. Homologues of characterised substrates of prokaryotic STYKs have also been identified. CONCLUSION: The domains and domain architectures of most of the bacterial STYKs identified are very different from the known domain organisation in STYKs of eukaryotes. This observation highlights distinct biological roles of bacterial STYKs compared to eukaryotic STYKs. Bacterial STYKs reveal high diversity in domain organisation. Some of the modular organisations conserved across diverse bacterial species suggests their central role in bacterial physiology. Unique domain architectures of few other groups of STYKs reveal recruitment of functions specific to the species.

Amino Acid Sequence↗

PubMed2005

Interaction preferences across protein-protein interfaces of obligatory and non-obligatory components are different.

BACKGROUND: A polypeptide chain of a protein-protein complex is said to be obligatory if it is bound to another chain throughout its functional lifetime. Such a chain might not adopt the native fold in the unbound form. A non-obligatory polypeptide chain associates with another chain and dissociates upon molecular stimulus. Although conformational changes at the interaction interface are expected, the overall 3-D structure of the non-obligatory chain is unaltered. The present study focuses on protein-protein complexes to understand further the differences between obligatory and non-obligatory interfaces. RESULTS: A non-obligatory chain in a complex of known 3-D structure is recognized by its stable existence with same fold in the bound and unbound forms. On the contrary, an obligatory chain is detected by its existence only in the bound form with no evidence for the native-like fold of the chain in the unbound form. Various interfacial properties of a large number of complexes of known 3-D structures thus classified are comparatively analyzed with an aim to identify structural descriptors that distinguish these two types of interfaces. We report that the interaction patterns across the interfaces of obligatory and non-obligatory components are different and contacts made by obligatory chains are predominantly non-polar. The obligatory chains have a higher number of contacts per interface (20 +/- 14 contacts per interface) than non-obligatory chains (13 +/- 6 contacts per interface). The involvement of main chain atoms is higher in the case of obligatory chains (16.9 %) compared to non-obligatory chains (11.2 %). The beta-sheet formation across the subunits is observed only among obligatory protein chains in the dataset. Apart from these, other features like residue preferences and interface area produce marginal differences and they may be considered collectively while distinguishing the two types of interfaces. CONCLUSION: These results can be useful in distinguishing the two types of interfaces observed in structures determined in large-scale in the structural genomics initiatives, especially for those multi-component protein assemblies for which the biochemical characterization is incomplete.

Animals↗

PubMed2005

PRODOC: a resource for the comparison of tethered protein domain architectures with in-built information on remotely related domain families.

PROtein Domain Organization and Comparison (PRODOC) comprises several programs that enable convenient comparison of proteins as a sequence of domains. The in-built dataset currently consists of approximately 698 000 proteins from 192 organisms with complete genomic data, and all the SWISSPROT proteins obtained from the Pfam database. All the entries in PRODOC are represented as a sequence of functional domains, assigned using hidden Markov models, instead of as a sequence of amino acids. On average 69% of the proteins in the proteomes and 49% of the residues are covered by functional domain assignments. Software tools allow the user to query the dataset with a sequence of domains and identify proteins with the same or a jumbled or circularly permuted arrangement of domains. As it is proposed that proteins with jumbled or the same domain sequences have similar functions, this search tool is useful in assigning the overall function of a multi-domain protein. Unique features of PRODOC include the generation of alignments between multi-domain proteins on the basis of the sequence of domains and in-built information on distantly related domain families forming superfamilies. It is also possible using PRODOC to identify domain sharing and gene fusion events across organisms. An exhaustive genome-genome comparison tool in PRODOC also enables the detection of successive domain sharing and domain fusion events across two organisms. The tool permits the identification of gene clusters involved in similar biological processes in two closely related organisms. The URL for PRODOC is http://hodgkin.mbu.iisc.ernet.in/~prodoc.

Databases, Protein↗

PubMed2005

Use of multiple profiles corresponding to a sequence alignment enables effective detection of remote homologues.

MOTIVATION: Position specific scoring matrices (PSSMs) corresponding to aligned sequences of homologous proteins are commonly used in homology detection. A PSSM is generated on the basis of one of the homologues as a reference sequence, which is the query in the case of PSI-BLAST searches. The reference sequence is chosen arbitrarily while generating PSSMs for reverse BLAST searches. In this work we demonstrate that the use of multiple PSSMs corresponding to a given alignment and variable reference sequences is more effective than using traditional single PSSMs and hidden Markov models. RESULTS: Searches for proteins with known 3-D structures have been made against three databases of protein family profiles corresponding to known structures: (1) One PSSM per family; (2) multiple PSSMs corresponding to an alignment and variable reference sequences for every family; and (3) hidden Markov models. A comparison of the performances of these three approaches suggests that the use of multiple PSSMs is most effective. CONTACT: ns@mbu.iisc.ernet.in.

Algorithms↗

PubMed2005

Interaction interfaces of protein domains are not topologically equivalent across families within superfamilies: Implications for metabolic and signaling pathways.

Using a data set of aligned protein domain superfamilies of known three-dimensional structure, we compared the location of interdomain interfaces on the tertiary folds between members of distantly related protein domain superfamilies. The data set analyzed is comprised of interdomain interfaces, with domains occurring within a polypeptide chain and those between two polypeptide chains. We observe that, in general, the interfaces between protein domains are formed entirely in different locations on the tertiary folds in such pairs. This variation in the location of interface happens in protein domains involved in a wide range of functions, such as enzymes, adapters, and domains that bind protein ligands, or cofactors. While basic biochemical functionality is preserved at the domain superfamily level, the effect of biochemical function on protein assemblies is different in these protein domains related by superfamily. The divergence between proteins, in most cases, is coupled with domain recruitment, with different modes of interaction with the recruited domain. This is in complete contrast to the observation that in closely related homologous protein domains, almost always the interaction interfaces are topologically equivalent. In a small subset of interacting domains within proteins related by remote homology, we observe that the relative positioning of domains with respect to one another is preserved. Based on the analysis of multidomain proteins of known or unknown structure, we suggest that variation in protein-protein interactions in members within a superfamily could serve as diverging points in otherwise parallel metabolic or signaling pathways. We discuss a few representative cases of diverging pathways involving domains in a superfamily.

Animals↗

PubMed2005

A genomic perspective of protein kinases in Plasmodium falciparum.

Protein kinases are central to regulation of cellular signaling in the eukaryotes. Well-conserved and lineage-specific protein kinases have previously been identified from various completely sequenced genomes of eukaryotes. The current work describes a genome-wide analysis for protein kinases encoded in the Plasmodium falciparum genome. Using a few different profile matching methods, we have identified 99 protein kinases or related proteins in the parasite genome. We have classified these kinases into subfamilies and analyzed them in the context of noncatalytic domains that occur in these catalytic kinase domain-containing proteins. Compared to most eukaryotic protein kinases, these sequences vary significantly in terms of their lengths, inserts in catalytic domains, and co-occurring domains. Catalytic and noncatalytic domains contain long stretches of repeats of positively charged and other polar amino acids. Various components of the cell cycle, including 4 cyclin-dependent kinase (CDK) homologues, 2 cyclins, 1 CDK regulatory subunit, and 1 kinase-associated phosphatase, are identified. Identification of putative mitogen-activated protein (MAP) Kinase and MAP Kinase Kinase of P. falciparum suggests a new paradigm in the highly conserved signaling pathway of eukaryotes. The calcium-dependent kinase family, well represented in P. falciparum, shows varying domain combinations with EF-hands and pleckstrin homology domains. The analysis reveals a new subfamily of protein kinases having limited sequence similarity with previously known subfamilies. A new transmembrane kinase with 6 membrane-spanning regions is identified. Putative apicoplast targeting sequences have been detected in some of these protein kinases, suggesting their export to the apicoplast.

Animals↗