NREP

NREP
National Center for Biotechnology Information, U.S. National Library of Medicine · Public domain · source
Name	NREP
Uniprot	P27457
Organism	Homo sapiens
Chromosome	5q35
Length	129 aa
Synonyms	P311 protein

NREP is a small, highly conserved protein expressed in vertebrate tissues implicated in cell migration, wound healing, and fibrogenesis. First characterized in developmental and neural studies, it has been studied across model organisms and clinical contexts for roles in cytoskeletal dynamics and extracellular matrix interactions. The protein is encoded by a single exon gene and participates in signaling pathways linked to transcriptional regulation, integrin-mediated adhesion, and transforming growth factor responses.

Nomenclature and identifiers

The gene is listed under several standardized identifiers including the HGNC and Entrez Gene entries used by resources such as UniProt, Ensembl, RefSeq, OMIM, and GeneCards. Protein nomenclature includes the alternative name "P311" which appears in literature alongside the systematic symbol used in genome annotations. Cross-references are commonly made to proteomic databases like PeptideAtlas and structural repositories such as Protein Data Bank for homologous regions. Clinical databases such as ClinVar and variant catalogs curated by dbSNP index disease-associated alleles reported in population studies.

Gene and protein structure

The coding sequence maps to human chromosome 5 at cytoband 5q35 and is encoded by a single exon, producing a 129–amino-acid polypeptide. Comparative genomics shows orthologs conserved in Mus musculus, Rattus norvegicus, Danio rerio, and Xenopus laevis, indicating evolutionary conservation across vertebrates. Predicted secondary structure comprises short alpha-helices and intrinsically disordered regions identified by algorithms implemented in PSIPRED and IUPred. Post-translational modifications reported include phosphorylation sites detectable by mass spectrometry datasets in PhosphoSitePlus and ubiquitination marks cataloged in proteome-wide surveys. Structural modeling draws on templates from the Protein Data Bank for low-complexity motifs, and protein–protein interaction interfaces have been mapped by crosslinking and co-immunoprecipitation studies deposited in BioGRID and IntAct.

Expression and regulation

Transcript and protein expression have been profiled in normal and pathological tissues using resources such as the Human Protein Atlas, GTEx Project, and microarray compendia from NCBI GEO. High expression is documented in developing brain regions, dermal fibroblasts, and injured skeletal muscle, with inducible upregulation following tissue damage and during epithelial–mesenchymal transitions studied in models of wound healing and fibrosis. Regulatory control involves transcription factors including SOX2, AP-1 (Fos/Jun), and SMAD3 downstream of transforming growth factor-beta signaling cascades. MicroRNA-mediated post-transcriptional regulation has been reported for members of the miR-29 family and other noncoding RNAs cataloged by miRBase. Epigenetic marks at the locus, including histone modifications and DNA methylation patterns, have been profiled in datasets from ENCODE and the Roadmap Epigenomics Project.

Biological function and mechanism

Functional studies implicate the protein in modulation of cell motility via interactions with cytoskeletal regulators such as RhoA, Rac1, and Cdc42, and with focal adhesion components including vinculin and talin. It influences extracellular matrix remodeling by affecting expression of collagen genes like COL1A1 and matrix metalloproteinases such as MMP2 and MMP9. Mechanistically, the protein has been proposed to act as a scaffold linking signaling complexes to translational regulation machinery involving eIF4E and ribosomal subunits, contributing to rapid local protein synthesis during migration. In neuronal contexts, it participates in neurite outgrowth and synaptic plasticity pathways associated with receptors like TrkB and guidance cues including Netrin-1.

Clinical significance and disease associations

Altered expression has been observed in fibrotic disorders of the lung, liver, and skin, with correlative studies in cohorts assembled by consortia such as the IPF Network and European Liver Transplant Registry. Overexpression promotes myofibroblast differentiation characterized by upregulation of ACTA2 (alpha-smooth muscle actin), while loss-of-function approaches reduce scar formation in preclinical fibrosis models. Associations with tumor progression have been reported in studies of glioblastoma, breast carcinoma, and hepatocellular carcinoma, where expression correlates with invasive phenotypes and patient outcomes in datasets from TCGA and ICGC. Single-nucleotide variants and rare mutations cataloged in ClinVar have been tentatively linked to developmental anomalies in case series, though causal relationships remain under investigation in cohorts coordinated by Decipher and national genomics projects.

Experimental models and research methods

Experimental interrogation utilises genetic models including knockout and transgenic mice generated by consortia such as the International Knockout Mouse Consortium and conditional alleles employed with Cre drivers like Pax3-Cre and Col1a2-Cre. In vitro systems include primary human dermal fibroblasts, neuronal cultures derived from induced pluripotent stem cells characterized by Takashi Yoshiki-style protocols, and immortalized cell lines such as HEK293 and NIH 3T3 for mechanistic assays. Techniques applied range from CRISPR–Cas9 genome editing and RNA interference to proteomics using tandem mass spectrometry in facilities affiliated with ProteomicsDB and imaging by super-resolution platforms developed at institutes like the Max Planck Institute. Functional readouts commonly involve wound-healing scratch assays, transwell migration, collagen gel contraction, and organotypic culture systems used in translational studies.

Category:Human proteins