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Results for “multigene typing”

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PubMed1990

Molecular cloning and characterization of retrovirus-like intracisternal type A particle genes (IAP) present in the Chinese hamster genome.

Endogenous retrovirus-like sequences that are homologous to the multigenic murine and Syrian hamster intracisternal type A particle (IAP) genes can be detected in very few copies in the Chinese hamster (CH) genome. They were cloned from a CHO gene library and two recombinants, harboring the major IAP-like DNA genes characterized by Southern blot hybridization after DNA digestion with several restriction enzymes. The IAP DNA inserts of the two clones analyzed were 4.70 and 8.04 kb respectively, allowing us to construct a physical map of our Chinese hamster clone that represents an almost complete IAP element.

Animals↗

PubMed2001

Immune-type receptor genes in zebrafish share genetic and functional properties with genes encoded by the mammalian leukocyte receptor cluster.

An extensive, highly diversified multigene family of novel immune-type receptor (nitr) genes has been defined in Danio rerio (zebrafish). The genes are predicted to encode type I transmembrane glycoproteins consisting of extracellular variable (V) and V-like C2 (V/C2) domains, a transmembrane region and a cytoplasmic tail. All of the genes examined encode immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic tail. Radiation hybrid panel mapping and analysis of a deletion mutant line (b240) indicate that a minimum of approximately 40 nitr genes are contiguous in the genome and span approximately 0.6 Mb near the top of zebrafish linkage group 7. One flanking region of the nitr gene complex shares conserved synteny with a region of mouse chromosome 7, which shares conserved synteny with human 19q13.3-q13.4 that encodes the leukocyte receptor cluster. Antibody-induced crosslinking of Nitrs that have been introduced into a human natural killer cell line inhibits the phosphorylation of mitogen-activated protein kinase that is triggered by natural killer-sensitive tumor target cells. Nitrs likely represent intermediates in the evolution of the leukocyte receptor cluster.

Amino Acid Sequence↗

PubMed1994

[Roles of anions in cells: studies on a Cl(-)-translocating ATPase and sulfate uptake system in Acetabularia acetabulum].

Biochemical and molecular biological approaches to two anion translocators, a Cl(-)-translocating ATPase and sulfate permease were described for Acetabularia acetabulum, a unicellular marine alga. The primary structures of an almost complete cDNA clone of the 50 kDa subunit and a partial cDNA clone of the 54 kDa subunit of the Cl(-)-ATPase were highly similar to the beta and alpha subunits of the F type ATPase, respectively. A partial cDNA clone encoding the alpha subunit of chloroplast ATPase, and partial cDNA clones coding for the beta subunits of chloroplast and mitochondrial ATPases were also obtained from A. acetabulum. The presence of a small multigene family for the F type ATPases with different ion specificities was strongly suggested for the organism. Sulfate uptake system in this organism was also studied and partial cDNA clones encoding CysA and sulfate binding proteins were obtained. ca. 1.7 kb RNA for cysA gene and 1.55 kb for sbp gene were detected by Northern analysis, respectively. A putative malK gene was also partially cloned.

Acetabularia↗

PubMed1995

Proteins of the Xenopus laevis zinc finger multigene family as targets for CK II phosphorylation.

Zn finger proteins (ZFPs) of the C2/H2 type in Xenopus laevis are encoded by a multigene family comprising several hundred members. Based upon conserved sequence features outside the Zn finger region, ZFPs can be subdivided into distinct subfamilies. Two of such subfamilies are characterized by conserved, N-terminal amino acid sequences termed the FAX and the FAR Domain. Here we present data suggesting that the zinc finger proteins of the FAR-ZFP subfamily are targets for CK II mediated phosphorylation. Expression of these proteins during oogenesis coincides with CK II activity in unfertilized eggs. Additionally, we have found that XlcOF 7.1, a member of the FAX-ZFP subfamily, is also phosphorylated by CK II. The target sites for in vitro phosphorylation are localized within the conserved N-terminal domains but not within the Zn finger regions. However, amino acid sequence comparison revealed that individual phosphoacceptor sites are not generally conserved among all members of the respective ZFP subfamilies. The relevance of a potential CK II phosphorylation for the regulation of ZFP activity in vivo is discussed.

Amino Acid Sequence↗

PubMed1994

Annexin II contains two types of Ca(2+)-binding sites.

The annexins are a multigene family of Ca(2+)-dependent phospholipid-binding proteins which contain novel types of Ca2+ sites. Using site-directed mutagenesis, we generated mutant proteins that show defects in the Ca(2+)-binding sites in a particular member of this family, the src tyrosine kinase substrate annexin II. Analysis of the relative Ca(2+)-binding affinities of annexin II mutants in a combined Ca2+/phospholipid-binding assay revealed two distinct types of Ca(2+)-binding sites. Three so-called type II sites are found in annexin repeats 2, 3 and 4 respectively. Two so-called type III sites are located in the first repeat and involve the glutamic acid residues at positions 52 and 95. Both types of sites were recently identified by X-ray crystallography in annexins V and I [Huber, Schneider, Mayr, Römisch and Paques (1990) FEBS Lett. 275, 15-21; Weng, Luecke, Song, Kang, Kim and Huber (1993) Protein Sci. 2, 448-458], indicating that similar principles govern Ca2+ binding to annexins in crystals and in solution. The two types of Ca(2+)-binding sites differ not only in their architecture but also in their affinity for the bivalent cation. The Ca2+ concentration needed for half-maximal phosphatidylserine binding is 5-10 microM for an annexin II derivative with intact type II but defective type III sites (TM annexin II) whereas a mutant protein containing defective type II but unaltered type III sites (CM annexin II) requires 200-300 microM Ca2+ for the same activity. Annexin II mutants with defects in the type II and/or type III sites also show different subcellular distributions. When expressed transiently in HeLa cells, TM annexin II acquires the typical location in the cortical cytoskeleton observed for the wild-type molecule. In contrast, CM annexin II remains essentially cytosolic, as does a mutant protein containing defects in both type II and type III Ca(2+)-binding sites (TCM annexin II). This indicates that the intracellular association of annexin II with the submembraneous cytoskeleton depends only on the occupation of type II Ca(2+)-binding sites.

Amino Acid Sequence↗

PubMed1983

Intermediate filaments as histologic markers: an overview.

Determination of the type of intermediate filaments (IFs) present in a cell or tissue can yield information about its origin. Thus cells can be grouped into six different classes, i.e. epithelial cells characterized by cytokeratins, most but not all neurones characterized by neurofilaments (NFs), glial cells characterized by the presence of glial fibrillary acidic filaments, muscle cells characterized by the presence of desmin filaments, mesenchymal cells and certain other nonepithelial cell types characterized by the presence of vimentin, and other cells that appear not to contain IFs. The assignments made by immunologic techniques are supported by protein chemistry of the isolated proteins. Information derived from protein sequences as well as from DNA sequences establish that the major intermediate-filament proteins are different but related molecules and show also that the alpha-keratins of wool belong to this multigene family. Applications of IF typing to human pathologic material, and especially to the different major subgroups of human tumors, are reviewed. Thus, for instance, carcinomas continue to express cytokeratins, many tumors of neuronal origin express NFs, gliomas express glial fibrillary acidic protein (GFA), rhabdomyosarcomas express desmin, and nonmuscle sarcomas express vimentin. Further subclassification of epithelial cells and carcinomas is discussed. The subdivisions obtained by IF typing are striking because they follow well-known histologic principles; thus IF typing seems useful in certain instances where diagnosis is difficult by conventional techniques.

Animals↗

PubMed1998

Homologues of vertebrate type I, II and III intermediate filament (IF) proteins in an invertebrate: the IF multigene family of the cephalochordate Branchiostoma.

We searched for functional homologues of the four subfamilies of vertebrate cytoplasmic intermediate filament (IF) proteins in the cephalochordate Branchiostoma. The epidermis contains in addition to IF proteins C2 and D1 two novel IF proteins E1 and E2. Both sequence comparisons as well as the obligatory heteropolymer formation by the recombinant proteins identify E1 as a type I keratin and E2 and D1 as type II keratins. In contrast the non-epidermal B1 forms as type III homologue homopolymeric IF. We propose that type I-III diversification of IF proteins is a property of the chordate branch of metazoa and discuss a possible origin of type IV neurofilaments.

Amino Acid Sequence↗

PubMed1995

Expression of Drosophila lamin C is developmentally regulated: analogies with vertebrate A-type lamins.

Vertebrate nuclear lamins form a multigene family with developmentally controlled expression. In contrast, invertebrates have long been thought to contain only a single lamin, which in Drosophila is the well-characterized lamin Dm0. Recently, however, a Drosophila cDNA clone (pG-IF) has been identified that codes for an intermediate filament protein which harbors a nuclear localization signal but lacks a carboxy-terminal CAAX motif. Based on these data the putative protein encoded by pG-IF was tentatively called Drosophila lamin C. To address whether the pG-IF encoded protein is expressed and whether it encodes a cytoplasmic intermediate filament protein or a nuclear lamin we raised antibodies against the recombinant pG-IF protein. The antibodies decorate the nuclear envelope in Drosophila Kc tissue culture cells as well as in salivary and accessory glands demonstrating that pG-IF encodes a nuclear lamin (lamin C). Antibody decoration, in situ hybridization, western and northern blotting studies show that lamin C is acquired late in embryogenesis. In contrast, lamin Dm0 is constitutively expressed. Lamin C is first detected in late stage 12 embryos in oenocytes, hindgut and posterior spiracles and subsequently also in other differentiated tissues. In third instar larvae lamins C and Dm0 are coexpressed in all tissues tested. Thus, Drosophila has two lamins: lamin Dm0, containing a CaaX motif, is expressed throughout, while lamin C, lacking a CaaX motif, is expressed only later in development. Expression of Drosophila lamin C is similar to that of vertebrate lamin A (plus C), which loses its CaaX motif during incorporation into the lamina.

Animals↗

PubMed1988

Chromosomal assignments of human type I and type II cytokeratin genes to different chromosomes.

The chromosomal location of representative members of the type I and type II subfamilies of the cytokeratin multigene family was determined using specific cDNA probes in Southern blot hybridization with DNA from somatic cell hybrids. Our results show that the gene encoding human type II cytokeratin 4 resides on chromosome 12 and that encoding type I cytokeratin 15 is located on chromosome 17. The results indicate that cytokeratins are not concentrated in only one cluster. The possibility of the existence of separate type I and type II cytokeratin gene clusters is discussed.

Blotting, Southern↗

PubMed2000

Localization of Idd11 using NOD congenic mouse strains: elimination of Slc9a1 as a candidate gene.

Type 1 diabetes is a multigenic autoimmune disease, the genetic basis for which is perhaps best characterized in the nonobese diabetic (NOD) mouse model. We previously located a NOD diabetes susceptibility locus, designated Idd11, on mouse Chromosome (Chr) 4 by analyzing diabetic backcross mice produced after crossing NOD/Lt with the nondiabetic resistant strain C57BL/6 (B6) strain. In order to confirm Idd11 and further refine its location, three NOD congenic mouse strains with different B6 derived intervals within Chr 4 were generated. Two of the congenic strains had a significant decrease in the cumulative incidence of diabetes compared with NOD/Lt control mice. The third NOD congenic strain, containing a B6 interval surrounding the Slc9a1 locus, was not protected against diabetes. These results define a new distal boundary for Idd11 and eliminate the Slc9a1 gene as a candidate. The Idd11 locus has now been definitively mapped to a 13cM interval on mouse Chr 4.

Alleles↗

PubMed1996

Localisation and differential expression of the fibroblast growth factor receptor (FGFR) multigene family in normal and atherosclerotic human arteries.

OBJECTIVE: Aberrant expression of FGF-1 and FGF-2 may be central to the atherosclerotic disease process, promoting both intimal hyperplasia and plaque neovascularisation. FGF-1 and FGF-2 mediate their biological effects by binding to a family of specific high-affinity cell surface receptors with protein tyrosine kinase activity. Four receptors have been identified in the human (FGFR1/flg gene product, FGFR2/bek gene product, FGFR3 and FGFR4), but little is known of their in vivo tissue distribution. Characterisation of the spatial distribution of the FGFR multigene family in both normal and atherosclerotic arteries is a prerequisite to further define the functional role of FGF-1 and FGF-2 in atherosclerosis. The objective of this study was to examine the cell-type-specific expression of the FGFR multigene family members in both normal and atherosclerotic human arteries. METHODS: FGFR expression was investigated immunocytochemically with polyclonal antisera to FGFR1-4 and by in situ hybridisation using FGFR1-4 riboprobes in archival material. Total cellular mRNA was analysed using poly d(T) and the levels correlated with the expression of FGFR1-4 mRNA. RESULTS: At the protein level, FGFR1-4 were expressed in the medial smooth muscle cells and adventitial vessels of normal arteries. In simple and advanced lesions, the expression profiles of FGFR1-4 showed variability between individual arteries, and cell-type-specific differential FGFR expression was apparent. Widespread co-expression of FGFR1 and FGFR2 was observed in intimal smooth muscle cells, foam cells and the plaque microvasculature of simple and advanced lesions. FGFR3 and FGFR4 exhibited more restricted patterns of distribution within the plaque. In situ hybridisation with poly d(T) confirmed high cellular transcriptional activity in archival atherosclerotic lesions. The high levels of total cellular mRNA and FGFR protein were not always reciprocated at the FGFR1-4 mRNA level, and only FGFR1 and FGFR2 mRNA transcripts were abundant in intimal lesions. CONCLUSION: These data provide evidence to suggest involvement of the FGF-FGFR multigene families in human atherogenesis. Differential FGFR expression in plaque subtypes may reflect distinct differences in receptor function which may be relevant to lesion progression during atherosclerosis.

Adult↗

PubMed1985

A complex set of early chorion DNA sequences from Bombyx mori.

A follicular cDNA library from Bombyx mori (576 clones) was screened to obtain a representative sample of chorion sequences differentially expressed during the early period of choriogenesis. Ten selected sequences were characterized by Northern analysis and by dot blots of stage-specific RNA. Five of these sequences (represented in the library by 24 clones) had the developmental specificity and transcript size expected of early chorion components; two sequences (37 clones) had the developmental specificity expected of middle and late chorion components; and three sequences (16 clones) were presumed to be non-chorion, since they are constitutive or disappear at the beginning of choriogenesis. The five recovered early chorion cDNA components have been sequenced, and define three distinct subfamilies of the chorion B multigene family, and two C type families. The complexity of the early chorion genes in B. mori is discussed.

Animals↗

PubMed1992

Antifreeze protein pseudogenes.

Three members, 11-3, F2 and 5a, of the type-I antifreeze protein (AFP) multigene family in winter flounder were sequenced. All three belong to the subset of AFP genes that are linked, but irregularly spaced, and show significant differences from the functional genes in tandem repeats. 11-3 and F2 appear to be pseudogenes. Their intron, 3'-exon and 3'-flanking DNAs are similar to those of other AFP genes, but their 5'-exon is either missing or extensively modified, and has stop codons present in all three reading frames. Based on a comparison of intron sequences of family members, 11-3/F2 may represent a residual progenitor AFP gene which was duplicated after reaching pseudogene status. The third gene, 5a, is remarkable in having a 3'-exon that encodes an exceptionally long, Ala-rich sequence that lacks any semblance of the 11-amino acid repeats found in 11-3, F2 and functional AFP genes. 5a might also be a pseudogene, because its presumed TATA box appears to have mutated.

Amino Acid Sequence↗

PubMed2001

Fibroblast growth factor-II gene therapy reverts the clinical course and the pathological signs of chronic experimental autoimmune encephalomyelitis in C57BL/6 mice.

The development of therapies aimed to promote remyelination is a major issue in chronic inflammatory demyelinating disorders of the central nervous system (CNS) such as multiple sclerosis (MS), where the permanent neurological impairment is due to the axonal loss resulting from recurrent episodes of immune-mediated demyelination. Here, we show that the intrathecal injection of a herpes simplex virus (HSV) type-1 replication-defective multigene vector, engineered with the human fibroblast growth factor (FGF)-II gene (TH:bFGF vector), was able to significantly revert in C57BL/6 mice the clinicopathological signs of chronic experimental autoimmune encephalomyelitis (EAE), the animal model of MS. The treatment with the TH:bFGF vector was initiated within 1 week after the clinical onset of EAE and was effective throughout the whole follow-up period (ie 60 days). The disease-ameliorating effect in FGF-II-treated mice was associated with: (1) CNS production of FGF-II from vector-infected cells which were exclusively located around the CSF space (ependymal, choroidal and leptomeningeal cells); (2) significant decrease (P < 0.01) of the number of myelinotoxic cells (T cells and macrophages) both in the CNS parenchyma and in the leptomeningeal space; and (3) significant increase (P < 0.01) of the number of oligodendrocyte precursors and of myelin-forming oligodendrocytes in areas of demyelination and axonal loss. Our results indicate that CNS gene therapy using HSV-1-derived vector coding for neurotrophic factors (ie FGF-II) is a safe and non-toxic approach that might represent a potential useful 'alternative' tool for the future treatment of immune-mediated demyelinating diseases.

Animals↗

PubMed1985

Patterns of expression and organization of cytokeratin intermediate filaments.

Cytokeratins are a large multigene family comprising two polypeptide types, i.e. acidic (type I) and basic (type II) ones, which are distinguished on the basis of immunological, peptide mapping, mRNA hybridization, and primary amino acid sequence data. The acidic (type I) cytokeratins can be subdivided into at least two different subtypes on the basis of their carboxy-terminal sequences. Considerable interspecies conservation of sequences exists, even extending to the 3'-non-coding mRNA regions. Different pairs of type I and II cytokeratins show different resistance to dissociation in urea. Sequence differences of the type I cytokeratins containing functional domains may be an explanation of the observed preference of co-expression with certain type II cytokeratins. The distribution of the different type I and II cytokeratins in normal epithelia and in carcinomas is differentiation related and can be used for cell typing and identification. The cell type-specific expression of cytokeratin polypeptides is recognized at both the protein and the mRNA level. The building block of cytokeratin IFs is a heterotypic tetramer, consisting of two type I and two type II polypeptides arranged in pairs of laterally aligned coiled coils. This principle of tetrameric organization is thought to be generally applicable to IFs.

Amino Acid Sequence↗

PubMed1995

[Genetic bases of cutaneous tumors].

Carcinogenesis is a multigenic phenomenon where 3 prevailing types of genes are involved: oncogenes which stimulate the cell proliferation, tumor suppressor genes which act as inhibitors and metastagenes which contribute to the tumor progress. In animal models it has been shown that epithelial skin carcinogenesis proceeds stepwise: initiation, promotion, premalignant progression and finally malignant conversion. The oncogene c-H-ras and the tumor suppressor gene P53 are the genes whose involvement in these steps of epithelial skin cancers are duly established. Less experimental data are available concerning melanoma. the role of the oncogene N-ras, the tumor suppressor gene MTS-1 (encoding for protein p16) ans the metastagene nm 23 has recently be emphasized. Some cytogenetic abnormalities on chromosomes 1, 6, 9, 10, 11 and 17 have also been observed and incite to look for other genes potentially involved in the development of this tumor.

Cell Transformation, Neoplastic↗

PubMed1999

Complexity and expression of the glutamine synthetase multigene family in the amphidiploid crop Brassica napus.

In the amphidiploid genome of oilseed rape (Brassica napus) the diploid ancestral genomes of B. campestris and B. oleracea have been merged. As a result of this crossing event, all gene loci, gene families, or multigene families of the A and C genome types encoding a certain protein are now combined in one plant genome. In the case of the multigene family for glutamine synthetase, the key enzyme of nitrogen assimilation, six different cDNA sequences were isolated from leaf and root specific libraries. One sequence pair (BnGSL1/BnGSL2) was characterized by the presence of amino-terminal transit peptides, a typical feature of all nuclear encoded chloroplast proteins. Two other cDNA pairs (BnGSR1-1/BnGSR1-2 and BnGSR2-1/BnGSR2-2) with very high homology between each other were found in a root specific cDNA library and represent protein subunits for cytosolic glutamine synthetase isoforms. Comparative PCR amplifications of genomic DNA isolated from B. napus, B. campestris and B. oleracea followed by sequence-specific restriction analyses of the PCR products permitted the assignment of the cDNA sequences to either the A genome type (BnGSL1/BnGSR1-1/BnGSR2-1) or the C genome type (BnGSL2/BnGSR1-2/BnGSR2-2). Consequently, the ancestral GS genes of B. campestris and B. oleracea are expressed simultaneously in oilseed rape. This result was also confirmed by RFLP (restriction fragment length polymorphism) analysis of RT-PCR products. In addition, the different GS genes showed tissue specific expression patterns which are correlated with the state of development of the plant material. Especially for the GS genes encoding the cytosolic GS isoform BnGSR2, a marked increase of expression could be observed after the onset of leaf senescence.

Blotting, Northern↗

PubMed1975

The humoral response of mouse spleen cells to two types of sheep erythrocytes. II. Evidence for gene expression in the B lymphocyte.

There is multigene control of the response of mouse spleen cells to two types of sheep erytrocytes (H and L). Discriminator strains of mice make a much higher response to extra antigens found only on H SRBC than to the shared antigens found on both types of erythrocyte. Non-discriminator strains respond only to the shared antigens, making a responses as great as the discriminator response to the extra antigens. The cell type in which this genetic control is expressed was investigated by a number of methods for studying the role of the macrophage, T cell, and B cell in the production of anti-SRBC response. The results provide no evidence that the gene(s) operate at the macrophage, T cell, or any other accessory cell level. The data from B cell-limiting dilution experiments are compatible with genetic expression at the B cell level.

Animals↗