PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Functional analysis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2005

Peroxisomal monodehydroascorbate reductase. Genomic clone characterization and functional analysis under environmental stress conditions.

In plant cells, ascorbate is a major antioxidant that is involved in the ascorbate-glutathione cycle. Monodehydroascorbate reductase (MDAR) is the enzymatic component of this cycle involved in the regeneration of reduced ascorbate. The identification of the intron-exon organization and the promoter region of the pea (Pisum sativum) MDAR 1 gene was achieved in pea leaves using the method of walking polymerase chain reaction on genomic DNA. The nuclear gene of MDAR 1 comprises nine exons and eight introns, giving a total length of 3,770 bp. The sequence of 544 bp upstream of the initiation codon, which contains the promoter and 5' untranslated region, and 190 bp downstream of the stop codon were also determined. The presence of different regulatory motifs in the promoter region of the gene might indicate distinct responses to various conditions. The expression analysis in different plant organs by northern blots showed that fruits had the highest level of MDAR. Confocal laser scanning microscopy analysis of pea leaves transformed with Agrobacterium tumefaciens having the binary vectors pGD, which contain the autofluorescent proteins enhanced green fluorescent protein and enhanced yellow fluorescent protein with the full-length cDNA for MDAR 1 and catalase, indicated that the MDAR 1 encoded the peroxisomal isoform. The functional analysis of MDAR by activity and protein expression was studied in pea plants grown under eight stress conditions, including continuous light, high light intensity, continuous dark, mechanical wounding, low and high temperature, cadmium, and the herbicide 2,4-dichlorophenoxyacetic acid. This functional analysis is representative of all the MDAR isoforms present in the different cell compartments. Results obtained showed a significant induction by high light intensity and cadmium. On the other hand, expression studies, performed by semiquantitative reverse transcription-polymerase chain reaction demonstrated differential expression patterns of peroxisomal MDAR 1 transcripts in pea plants grown under the mentioned stress conditions. These findings show that the peroxisomal MDAR 1 has a differential regulation that could be indicative of its specific function in peroxisomes. All these biochemical and molecular data represent a significant step to understand the specific physiological role of each MDAR isoenzyme and its participation in the antioxidant mechanisms of plant cells.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1999

The impact of functional analysis methodology on treatment choice for self-injurious and aggressive behavior.

Self-injurious behavior (SIB) and aggression have been the concern of researchers because of the serious impact these behaviors have on individuals' lives. Despite the plethora of research on the treatment of SIB and aggressive behavior, the reported findings have been inconsistent regarding the effectiveness of reinforcement-based versus punishment-based procedures. We conducted a literature review to determine whether a trend could be detected in researchers' selection of reinforcement-based procedures versus punishment-based procedures, particularly since the introduction of functional analysis to behavioral assessment. The data are consistent with predictions made in the past regarding the potential impact of functional analysis methodology. Specifically, the findings indicate that, once maintaining variables for problem behavior are identified, experimenters tend to choose reinforcement-based procedures rather than punishment-based procedures as treatment for both SIB and aggressive behavior. Results indicated an increased interest in studies on the treatment of SIB and aggressive behavior, particularly since 1988.

Aggression↗
PubMed2004

[Cardio-MRT. The multimodal functional analysis of the future].

Since initial reports in the early 1990s cardiac magnetic resonance imaging (CMR) has matured and is likely to become an established method for routine cardiac diagnostics. The development of faster gradient-echo sequences and stronger magnetic fields has led to improved temporal and spatial resolution. Myocardial viability can be examined by morphological and functional analysis. Contrast enhanced MRI (ceMRI), perfusion measurements and regional wall motion analysis are the major diagnostic tools. The ability to image in arbitrary double oblique planes provides comprehensive visualization of the heart. The introduction of the MR navigator technique allowed for free-breathing motion corrected 3D coronary MR angiography with improved spatial resolution. Using this approach proximal and mid parts of the coronary arteries have been visualized. Subsequently, sensitivity and specificity for the detection of significant coronary stenoses has been evaluated in a multicenter trial demonstrating good sensitivity and specificity for the detection of significant left main and three vessel disease. However, specificity for the detection of single vessel disease was relatively low. Improved motion compensation techniques and novel imaging sequences (SSFP) are currently under investigation to further refine this technique. Despite these promising results coronary MR-angiography is not likely to replace conventional coronary angiography especially with regard to in-plane spatial resolution, coronary collateralization and in-stent restenosis. In contrast, coronary MR-angiography can provide useful morphological informations including functional analysis of the coronary vascular bed. The combination of a conventional cathlab with CMR may provide CMR-guided myocardial interventions. With further improvements in the catheter technology, CMR interventions using real-time imaging guidance will allow to take advantage of the excellent soft tissue contrast of CMR and the simultaneous visualization of the pulmonary, aortic and coronary vessels. CMR is advantageous for screening and follow-up examinations, and it offers comprehensive assessment of cardiac morphology and function in one single examination.

Cardiomyopathies↗
PubMed1986

Two-color flow cytometry and functional analysis of lymphocytes cultured from human renal allografts: identification of a Leu-2+3+ subpopulation.

The phenotype of T lymphocyte subsets present in renal biopsies showing acute cellular allograft rejection in six patients on cyclosporine have been characterized in situ by immunoperoxidase staining, and after expansion in vitro in interleukin 2 (IL-2) by two-color flow cytometry, sorting, and functional analysis. After 8 to 42 days in organ culture, both Leu-3+ (CD4) and Leu-2+ (CD8) subsets were found in each culture, in a ratio that varied from 0.2 to 5.0, which was not significantly different than the results of in situ immunoperoxidase staining of the uncultured biopsy. The cultured cells were almost all Leu-4+ (CD3) T cells (89% +/- 4), which expressed the activation markers DR (82% +/- 6) and the IL 2 (CD25) receptor (15% +/- 4). The Leu-3+ cells were largely Leu-8- (90% +/- 6), whereas a minority of the Leu-2+ cells were Leu-15+ (CD11) (26% +/- 4). Only a small fraction of the Leu-2+ cells stained for Leu-7 (8% +/- 6). Functional analysis of FACS-purified Leu-2-3+ and Leu-2+3- populations indicated that both subsets proliferated in response to graft donor antigens in a mixed lymphocyte reaction (MLR) and produced IL 2. Only the Leu-2+3- population demonstrated donor-specific cytotoxic activity. A minor subpopulation in each culture were both Leu-3+ and Leu-2+ (2.0%). Leu-2+3+ cells from one biopsy were purified to homogeneity (99.8%), and were found to express the T cell antigen receptor complex Ti/CD3 (WT-31+, Leu-4+), but not the common thymocyte antigen CD1 (OKT6). The Leu-2+3+ cells neither responded in the MLR, nor showed any cytotoxic capacity. The Leu-2+3+ cells were capable of IL 2 but not interferon-gamma production. None of the purified cultures demonstrated NK activity. A subset of the purified Leu-2+3+ cells lost Leu-2+ during 1 to 3 wk in culture, and became Leu-2-3+. These studies provide evidence that the cells that infiltrate renal allografts during rejection include alloproliferative, lymphokine-producing cells of both Leu-2+ and Leu-3+ subsets. The Leu-2+3- cells are also highly cytotoxic against donor lymphocytes, indicating the presence of helper independent cytotoxic T cells. A minor population of Leu-2+3+ T cells that do not express donor specific function was also identified.

Antibodies, Monoclonal↗
PubMed2004

Functional analysis and treatment of inappropriate sexual behavior.

The results of a functional analysis showed that inappropriate sexual behaviors exhibited by a 9-year-old boy who had been diagnosed with traumatic brain injury were maintained by positive reinforcement in the form of social attention. An intervention consisting of functional communication training and extinction resulted in reduced levels of inappropriate sexual behaviors.

Aggression↗
PubMed2005

Cardiac functional analysis with multi-detector row CT and segmental reconstruction algorithm: comparison with echocardiography, SPECT, and MR imaging.

PURPOSE: To evaluate accuracy of cardiac functional analysis with multi-detector row computed tomography (CT) and segmental reconstruction algorithm over a range of heart rates. MATERIALS AND METHODS: Institutional review board approval was obtained. Informed consent was not required. Multi-detector row CT (500-msec rotation time, 8 x 1-mm detector collimation) and magnetic resonance (MR) imaging were performed in 50 patients (28 men, 22 women; age range, 46-84 years; mean age, 67 years). Two-dimensional echocardiography was performed in 41 patients, and electrocardiographically (ECG)-gated single photon emission computed tomography (SPECT) was performed in 27. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and left ventricular (LV) mass were estimated with multi-detector row CT and compared with values estimated with MR imaging, which served as the reference standard. Additionally, EF values estimated with multi-detector row CT, echocardiography, and SPECT were compared with those estimated with MR imaging. Systemic error and degree of agreement of global functional parameters measured with MR imaging and other modalities were assessed. In a second analysis, linear regression analysis was added. RESULTS: EF estimated with multi-detector row CT agreed and correlated well with EF estimated with MR imaging (bias +/- standard deviation, -1.2% +/- 4.6; r = 0.96). Agreement and correlation were similar for EDV (-0.35 mL +/- 15.2; r = 0.97), ESV (1.1 mL +/- 8.6; r = 0.99), and LV mass (2.5 mL +/- 15.0; r = 0.96). Standard deviation of EF difference between multi-detector row CT and MR imaging was significantly less than that between echocardiography and MR imaging (P < .001) or that between SPECT and MR imaging (P < .001). CONCLUSION: Various LV functional parameters were measured with multi-detector row CT with a segmental approach, and measurements correlated and agreed with those obtained with MR imaging. Moreover, functional analysis with multi-detector row CT was more accurate than that with two-dimensional echocardiography or ECG-gated SPECT.

Aged↗
PubMed1997

Metal-ion-mediated allosteric triggering of yeast pyruvate kinase. 1. A multidimensional kinetic linked-function analysis.

Regulation of the glycolytic pathway is considered to be primarily achieved by the carbon metabolites resulting from glucose metabolism [e.g., fructose 1,6-diphosphate (FDP), phosphoenolpyruvate (PEP), and citrate] and by the ATP charge of the cell. The divalent cations (e.g., Mg2+ and Mn2+) have not been considered as having regulatory roles in glycolysis, although they are involved in almost every enzyme-catalyzed reaction in the pathway. Using a kinetic linked-function analysis of steady-state kinetic data for the interactions of PEP, FDP, and Mn2+ with yeast pyruvate kinase (YPK), we have found that the divalent metal is the principal trigger of the allosteric responses observed with this enzyme. The interaction of Mn2+ to YPK enhances the interaction of FDP by -1.6 kcal/mol and the interaction of PEP by -2.8 kcal/mol. The simultaneous interaction of all three of these ligands to YPK is favored by -4.3 kcal/mol over the sum of their independent binding free energies. Surprisingly, the binding of the allosteric activator FDP does not directly influence the binding of the substrate PEP since a coupling free energy near zero was calculated for these two ligands. Thus, communication between the PEP and FDP sites occurs structurally through the metal by an allosteric relay mechanism. These conclusions are supported by results of a thermodynamic linked-function analysis of direct binding data for the interactions of PEP, FDP, and Mn2+ with YPK [Mesecar, A. D., & Nowak, T. (1997) Biochemistry (following paper in this series)]. Our findings raise important questions as to the possible roles of divalent metals in modulating multiligand interactions with YPK and in the regulation of the glycolytic pathway.

Adenosine Diphosphate↗
PubMed1995

Functional analysis of avian class I (BFIV) glycoproteins by epitope tagging and mutagenesis in vitro.

Similarities between the physical structures of avian and mammalian major histocompatibility complex (MHC) class I glycoproteins have been proposed based on comparative alignment of their amino acid sequences. To investigate the physical structure of the chicken class I glycoprotein, we cloned the cDNA representing the BFIV locus of the B21 haplotype. A unique, chimeric class I glycoprotein was constructed by incorporating an epitope tag (FLAG) at the N terminus. Monoclonal antibodies to the FLAG epitope served to monitor cell-surface expression for functional analysis of the BFIV21 class I glycoprotein. The chimeric class I glycoprotein was expressed in target cells using an avian leukosis virus (ALV)-derived retrovirus vector (RCASBP). The presence of the FLAG epitope did not interfere with either alloantibody recognition or cytotoxic T lymphocyte interaction. Functional analysis employing site-directed mutagenesis identified BF amino acid residues forming serologic epitopes as well as residues important in antigen presentation to ALV-induced cytotoxic T lymphocytes. BF residues 78 and 81, corresponding to HLA 79 and 82, form an antibody epitope with a slight effect on ALV antigen presentation, consistent with their predicted orientation based on the HLA-A2 crystal structure. Alignment of the BFIV21 sequence with previously published BFIV sequences revealed polymorphisms at position 34 (HLA 34), a monomorphic residues in HLA and H-2. Residue 34 is located in pocket B and is predicted to contact the main-chain carbon of peptides bound in HLA-A2. A site-directed substitution in BFIV residue 34 dramatically alters ALV antigen presentation by the BFIV21 class I glycoprotein. These data indicate that the physical molecular structure of the chicken MHC class I glycoprotein is similar to HLA.

Amino Acid Sequence↗
PubMed1994

Functional analysis of human bronchial mucosal T cells extracted with interleukin-2.

Functional analysis of T cells from the bronchial mucosa has been limited by difficulties in extracting T cells from this tissue. Because interleukin-2 (IL-2) is chemotactic for T cells, we determined whether this cytokine could be used to extract T cells from human bronchial wall (BW). Fresh tissue was obtained from 21 patients undergoing surgery for malignancy. Within the BW, 95% of T cells stained for the memory/activation marker CD45RO. When BW sections were incubated with IL-2 for 24 h, 88 to 91% of T cells emigrated into the culture medium. Compared with autologous blood T cells (also exposed to IL-2), these BW T cells expressed CD2 at a greater intensity and showed a fourfold reduction in cloning efficiency in response to phytohemagglutinin, and T-cell clones derived from the BW population displayed a tendency for higher interferon-gamma production. Furthermore, we were also able to extract and clone T cells from bronchoscopic biopsies in four subjects, suggesting that this method will provide a new avenue for examining T-cell function in airway inflammatory diseases.

Aged↗
PubMed2004

Functional analysis of recombinant human serum albumin domains for pharmaceutical applications.

PURPOSE: Functional analysis of the three recombinant human serum albumin (rHSA) domains and their potential as stand-alone proteins for use as drug delivery protein carriers. METHODS: Protein structure was examined by fluorescence and CD spectroscopy. Ligand binding was estimated by ultrafiltration. Antioxidant activity was estimated by measuring the quenching of dihydrorhodamine 123. Esterase-like activity and enolase-like activity were estimated from the rate of hydrolysis of p-nitrophenyl acetate and conversion of dihydrotestosterone from the 3-keto to 3-enol form, respectively. The domains of human serum albumin (HSA) were radiolabeled with 111In to evaluate their pharmacokinetics. RESULTS: The ligand binding ability of subsites Ia and Ib could not be detected in domain II. However, the binding of ligands to subsite Ic and site II were preserved in domain II and domain III, respectively. Domain III retained about 45% of its esterase-like activity, and weaker esterase-like activity was also observed in domain I. All domains showed low enolase-like activity in a pH 7.4 phosphate buffer, but domain II had higher activity in a pH 9.2 carbonate buffer. Domain I exhibited antioxidant activity comparable to that of rHSA. All three of the 111In-radiolabeled domains were rapidly eliminated from HSA, with high accumulation in the kidneys. CONCLUSION: Domain I of HSA has great potential for further development as a drug delivery protein carrier, due to its favorable properties and the presence of a free cysteine residue.

Algorithms↗
PubMed1981

About the possibilities of registration of drug influence by means of radiocardiographic function analysis.

Changes in cardiac dynamics were analyzed by means of radiocardiographic function analysis under an infusion of epinephrine using the method of RAB. Typical changes in heart rate, stroke volume and blood pressure were observed after the application of epinephrine. Compared to examinations under physical exercise in case of healthy control subjects there was no typical decrease of enddiastolic volume dependent on the heart rate. Ejection time and ejection velocity was placed within the variation compared to values of a control group under physical exercise but there was a steeper increase of the curve under the effect of epinephrine. Under the influence of Solcoseryl no significant change could be observed in this series of tests compared to the basic values. The effect of epinephrine was changed by Solcoseryl in the way of an essentially smaller rise in heart rate and of a definite prolongation in diastolic time. A change in ejection time under the influence of epinephrine after the application of Solcoseryl could not be found. This allows the conclusion, that under the influence of Solcoseryl and after the administration of epinephrine better conditions for the metabolic restitution of heart muscle are given and consequently a direct effect of Solcoseryl on the heart muscle can be assumed.

Actihaemyl↗
PubMed1994

Discriminant function analysis of body surface potential maps in acute myocardial infarction.

Using a newly developed 64-electrode portable mapping device, QRS and ST-T isointegral maps were compared in 194 control subjects and 101 patients. One hundred ninety-four control subjects (mean age, 48 years; 120 men) with no history of cardiac disease were selected randomly and mapped. One hundred one patients (mean age, 62 years; 77 men) were mapped at presentation of chest pain suggestive of first myocardial infarction (MI); all patients had classic 12-lead electrocardiographic findings--46 with anterior and 55 with inferior MI. The diagnosis was confirmed in all cases by a significant rise in serial cardiac enzymes. The mean delay between onset of chest pain to map recording was 163 minutes. Of the 101 patients, 78 were first mapped outside the hospital. Applying discriminant function analysis to the isointegral measurements made on the control subjects and on the first map of MI patients achieved a correct classification of 97% of the control subjects (189 of 194) and 72% of the anterior (33 of 46) and 76% of the inferior (42 of 55) MI groups. This preliminary study suggests that discriminant function analysis, based on isointegral maps, not only provides a method of separating control subjects from MI patients but that it can also differentiate between types of infarct. Further studies are required to improve the predictive values of discriminant function and to extend the methodology to assess both the site and size of MI.

Adult↗
PubMed1996

Functional analysis of a p21WAF1,CIP1,SDI1 mutant (Arg94 --> Trp) identified in a human breast carcinoma. Evidence that the mutation impairs the ability of p21 to inhibit cyclin-dependent kinases.

Human p21 (also known as WAF1, CIP1, or SDI1) is a dual inhibitor of cyclin dependent kinases (CDKs) and the replication factor PCNA, which plays a role as a downstream mediator of the cell-cycle arrest induced by the tumor suppressor p53. To determine whether inactivation of downstream targets of p53 might contribute to cellular transformation, we have examined the integrity of the p21 gene in 36 invasive ductal breast carcinomas. Direct sequence analysis of the polymerase chain reaction-amplified p21 gene revealed a C to T transition in codon 94 that caused the substitution of a tryptophan for an arginine in a tumor specimen. This mutation was not detected in normal DNA extracted from the same patient nor in a polymerase chain reaction-restriction fragment length polymorphism of 50 unrelated individuals, indicating that it corresponds to a tumor-specific alteration. Functional analysis of the p21(R94W) protein produced in different eukaryotic and prokaryotic expression systems revealed that this mutation impaired the ability of p21 to inhibit CDKs. By contrast, the R94W mutant was unaltered in its ability to promote cyclin-CDK association as well as in its ability to bind proliferating cell nuclear antigen, thus leaving its putative functions as kinase activator or as inhibitor of replicative DNA synthesis intact. On the basis of these functional analysis, we propose that the Arg residue at position 94 is important for the CDK inhibitory role of p21.

Arginine↗
PubMed2003

Structure of gene flanking regions and functional analysis of sequences upstream of the rat hsp70.1 stress gene.

We present structural and comparative analysis of the flanking regions of the rat hsp70.1 stress gene. Several repetitive sequences, microsatellites and short interspersed repetitive elements (SINEs) were found, as well as a significant gap in the 3' UTR, as compared to the orthologous mouse gene. We also show that the complex microsatellite region composed of partially overlapping inverted repeat and long homopurine-homopyrimidine sequence, which is localized 1.8 kbp upstream of the transcription start site, is capable to adopt non-B DNA structures (an H-DNA and a cruciform structure) in vitro. Functional analysis performed with the use of various fragments of the 5'end flanking regions ligated to the chloramphenicol acetyltransferase (CAT) reporter gene revealed a crucial role of cooperation between heat shock element (HSE) regulatory sequences, while none of the three HSEs alone is able to drive efficient heat induced transcription of the reporter gene. We also found that the microsatellite region does not influence transcription by itself, however, it abolishes the effect of the adjacent putative silencing element. To our knowledge, this is a first extensive structural and functional analysis of the promoter region of the mammalian heat inducible hsp70i gene localized distally to the hsp70-related spermatid-specific gene in the major histocompatibility complex III.

3' Flanking Region↗
PubMed2006

Implications for molecular mechanisms of glycoprotein hormone receptors using a new sequence-structure-function analysis resource.

Comparison between wild-type and mutated glycoprotein hormone receptors (GPHRs), TSH receptor, FSH receptor, and LH-chorionic gonadotropin receptor is established to identify determinants involved in molecular activation mechanism. The basic aims of the current work are 1) the discrimination of receptor phenotypes according to the differences between activity states they represent, 2) the assignment of classified phenotypes to three-dimensional structural positions to reveal 3) functional-structural hot spots and 4) interrelations between determinants that are responsible for corresponding activity states. Because it is hard to survey the vast amount of pathogenic and site-directed mutations at GPHRs and to improve an almost isolated consideration of individual point mutations, we present a system for systematic and diversified sequence-structure-function analysis (http://www.fmp-berlin.de/ssfa). To combine all mutagenesis data into one set, we converted the functional data into unified scaled values. This at least enables their comparison in a rough classification manner. In this study we describe the compiled data set and a wide spectrum of functions for user-driven searches and classification of receptor functionalities such as cell surface expression, maximum of hormone binding capability, and basal as well as hormone-induced Galphas/Galphaq mediated cAMP/inositol phosphate accumulation. Complementary to known databases, our data set and bioinformatics tools allow functional and biochemical specificities to be linked with spatial features to reveal concealed structure-function relationships by a semiquantitative analysis. A comprehensive discrimination of specificities of pathogenic mutations and in vitro mutant phenotypes and their relation to signaling mechanisms of GPHRs demonstrates the utility of sequence-structure-function analysis. Moreover, new interrelations of determinants important for selective G protein-mediated activation of GPHRs are resumed.

Animals↗
PubMed2001

Salvaged limbs after tibial shaft fractures with extensive soft-tissue injury: a biopsychosocial function analysis.

BACKGROUND: The purpose of this study was to perform a biopsychosocial function analysis of the outcome in patients with a salvaged leg after tibial shaft fractures associated with extensive soft-tissue injury. METHODS: A retrospective review of 18 consecutive patients with tibial shaft fractures and extensive soft-tissue damage with a mean Injury Severity Score of 31 was undertaken. All patients were assessed for their physical function, psychological status, and general function. RESULTS: The range of motion and torque of the ankle joint were severely affected. The knee joint was affected, but only with regard to the torque during concentric muscular activities. Nottingham Health Profile scores showed that the general and social function for these patients were significantly affected. Five of 18 patients suffered from depression. CONCLUSION: Salvage procedures should be advocated if possible, but careful selection of patients on the basis of mental and social factors is crucial for the outcome.

Adaptation, Psychological↗
PubMed2006

Comparative analysis of HOG pathway proteins to generate hypotheses for functional analysis.

Comparative genomics allows comparison of different proteins that execute presumably identical functions in different organisms. In contrast to paralogues, orthologues per definition perform the same function and interact with the same partners and, consequently, should display conservation in all these properties. We have employed 20 fungal genomes to analyse key components of the high osmolarity glycerol signalling pathway of Saccharomyces cerevisiae. Among the proteins scrutinised are a complete phosphotransfer module, a MAP kinase, two scaffold proteins, one of which is also a MAPKK, and two transcription factors. Sequence alignments, domain structure and size analysis, combined with the rich information available in the literature, allowed us to probe previous structural and functional studies and to generate hypotheses for future experimental studies. Although certain domains are too highly conserved across fungal species for meaningful comparative studies, others, like interaction domains, can be studied in closely related species. Moreover, putative functionally relevant sites for protein modifications can be identified in such comparative studies. We provide several relevant examples and present a number of previously un(der)characterised domains of potential functional significance in osmosensing and signal transduction. We propose that any functional protein analysis in fungi should make use of the unique resource that fungal genome sequences offer.

Basic-Leucine Zipper Transcription Factors↗