Human Gene LAMB2 (uc003cwe.3) Description and Page Index
Description: Homo sapiens laminin, beta 2 (laminin S) (LAMB2), mRNA. RefSeq Summary (NM_002292): Laminins, a family of extracellular matrix glycoproteins, are the major noncollagenous constituent of basement membranes. They have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins, composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively), form a cruciform structure consisting of 3 short arms, each formed by a different chain, and a long arm composed of all 3 chains. Each laminin chain is a multidomain protein encoded by a distinct gene. Several isoforms of each chain have been described. Different alpha, beta and gamma chain isomers combine to give rise to different heterotrimeric laminin isoforms which are designated by Arabic numerals in the order of their discovery, i.e. alpha1beta1gamma1 heterotrimer is laminin 1. The biological functions of the different chains and trimer molecules are largely unknown, but some of the chains have been shown to differ with respect to their tissue distribution, presumably reflecting diverse functions in vivo. This gene encodes the beta chain isoform laminin, beta 2. The beta 2 chain contains the 7 structural domains typical of beta chains of laminin, including the short alpha region. However, unlike beta 1 chain, beta 2 has a more restricted tissue distribution. It is enriched in the basement membrane of muscles at the neuromuscular junctions, kidney glomerulus and vascular smooth muscle. Transgenic mice in which the beta 2 chain gene was inactivated by homologous recombination, showed defects in the maturation of neuromuscular junctions and impairment of glomerular filtration. Alternative splicing involving a non consensus 5' splice site (gc) in the 5' UTR of this gene has been reported. It was suggested that inefficient splicing of this first intron, which does not change the protein sequence, results in a greater abundance of the unspliced form of the transcript than the spliced form. The full-length nature of the spliced transcript is not known. [provided by RefSeq, Aug 2011]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications. ##Evidence-Data-START## Transcript exon combination :: SRR1660807.197004.1, SRR1803613.286762.1 [ECO:0000332] RNAseq introns :: mixed/partial sample support SAMEA1965299, SAMEA1966682 [ECO:0000350] ##Evidence-Data-END## ##RefSeq-Attributes-START## MANE Ensembl match :: ENST00000305544.9/ ENSP00000307156.4 RefSeq Select criteria :: based on conservation, expression, longest protein ##RefSeq-Attributes-END## Transcript (Including UTRs) Position: hg19 chr3:49,158,547-49,170,599 Size: 12,053 Total Exon Count: 32 Strand: - Coding Region Position: hg19 chr3:49,158,659-49,170,300 Size: 11,642 Coding Exon Count: 32
ID:LAMB2_HUMAN DESCRIPTION: RecName: Full=Laminin subunit beta-2; AltName: Full=Laminin B1s chain; AltName: Full=Laminin-11 subunit beta; AltName: Full=Laminin-14 subunit beta; AltName: Full=Laminin-15 subunit beta; AltName: Full=Laminin-3 subunit beta; AltName: Full=Laminin-4 subunit beta; AltName: Full=Laminin-7 subunit beta; AltName: Full=Laminin-9 subunit beta; AltName: Full=S-laminin subunit beta; Short=S-LAM beta; Flags: Precursor; FUNCTION: Binding to cells via a high affinity receptor, laminin is thought to mediate the attachment, migration and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. SUBUNIT: Laminin is a complex glycoprotein, consisting of three different polypeptide chains (alpha, beta, gamma), which are bound to each other by disulfide bonds into a cross-shaped molecule comprising one long and three short arms with globules at each end. Beta-2 is a subunit of laminin-3 (laminin-121 or S-laminin), laminin-4 (laminin-221 or S-merosin), laminin-7 (laminin-321 or KS-laminin), laminin-9 (laminin-421), laminin-11 (laminin-521), laminin-14 (laminin-423) and laminin-15 (laminin-523). SUBCELLULAR LOCATION: Secreted, extracellular space, extracellular matrix, basement membrane. Note=S-laminin is concentrated in the synaptic cleft of the neuromuscular junction. DOMAIN: The alpha-helical domains I and II are thought to interact with other laminin chains to form a coiled coil structure. DOMAIN: Domains VI and IV are globular. DISEASE: Defects in LAMB2 are the cause of Pierson syndrome (PIERSS) [MIM:609049]; also known as microcoria-congenital nephrotic syndrome. Pierson syndrome is characterized by nephrotic syndrome with neonatal onset, diffuse mesangial sclerosis and eye abnormalities with microcoria as the leading clinical feature. Death usually occurs within the first weeks of life. Disease severity depends on the mutation type: nontruncating LAMB2 mutations may display variable phenotypes ranging from a milder variant of Pierson syndrome to isolated congenital nephrotic syndrome. DISEASE: Defects in LAMB2 are the cause of nephrotic syndrome type 5 with or without ocular abnormalities (NPHS5) [MIM:614199]. NPHS5 is a renal disease characterized clinically by proteinuria, hypoalbuminemia, hyperlipidemia and edema. Kidney biopsies show non-specific histologic changes such as focal segmental glomerulosclerosis and diffuse mesangial proliferation. Some affected individuals have an inherited steroid-resistant form and progress to end-stage renal failure. NPHS5 is characterized by very early onset of progressive renal failure. A subset of patients may develop mild ocular anomalies, such as myopia, nystagmus, and strabismus. SIMILARITY: Contains 13 laminin EGF-like domains. SIMILARITY: Contains 1 laminin IV type B domain. SIMILARITY: Contains 1 laminin N-terminal domain. WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/LAMB2";
Genetic Association Studies of Complex Diseases and Disorders
Genetic Association Database (archive): LAMB2 CDC HuGE Published Literature: LAMB2 Positive Disease Associations: nephrotic syndrome Related Studies:
nephrotic syndrome Hinkes, B. G. et al. 2007, Nephrotic Syndrome in the First Year of Life, Pediatrics 2007.
First, two thirds of nephrotic syndrome manifesting in the first year of life can be explained by mutations in 4 genes only (NPHS1, NPHS2, WT1, or LAMB2).
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on P55268
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.