High impact information on Lamc1

• Production of laminin B2 chain protein and messenger RNA by a murine neutrophil precursor cell line, 32Dc13 [1].
• Lamb1(-/-) embryos are similar to Lamc1(-/-) embryos in that they lack basement membranes and do not survive beyond embryonic day (E) 5 [2].
• The laminin gamma1 chain has been shown by targeted mutation to be required for endodermal differentiation and formation of basement membranes; Lamc1(-/-) embryos die within a day of implantation [2].
• We have now selectively deleted the sequence coding for the 56 amino acid nidogen-binding site, gamma1III4, within the Lamc1 gene by gene targeting [3].
• In this report, we have screened a mouse genomic library with a 5' portion of the laminin B2 chain cDNA and isolated two genomic clones which contain the first and second exons [4].

Biological context of Lamc1

• The gene for retinal rod 33-kDa protein is on mouse chromosome 1, near Lamb2 [5].
• Antibodies against the nidogen binding site on laminin B2 chain perturbed epithelial development in vitro in embryonic kidney and lung [6].
• The laminin B2 chain promoter contains unique repeat sequences and is active in transient transfection [4].
• We have isolated and sequenced overlapping mouse laminin B2 chain cDNA clones covering 7562 base pairs [7].
• Nuclear extracts from IL-1 beta-treated GEC showed increased binding to the immunoglobulin kappa B enhancer element and to a kappa B consensus sequence from the murine laminin B2 chain promoter in an electrophoretic mobility-shift assay (EMSA) [8].

Anatomical context of Lamc1

• Using a retinal cDNA from the rat and somatic cell hybrids, we have mapped the gene corresponding to this protein to mouse Chromosome 1 and, by analyzing the progeny of an intersubspecific backcross, have positioned it near Lamb2 (the beta 2 chain of laminin) [5].
• In order to define the individual roles and interactions between these factors in endodermal differentiation, we have used embryoid bodies derived from Lamc1(-/-) embryonic stem cells that lack basement membranes [9].
• To determine whether laminin B2 chain mRNA levels change in response to cytokines, total mRNA from rat glomerular epithelial cells (GEC) grown in culture was analyzed by Northern blots [8].

Physical interactions of Lamc1

• The immunoglobulin kappa B and the laminin B2 chain kappa B-like motifs competed for the same DNA binding activity in nuclear extracts from IL-1 beta-treated GEC [8].

Regulatory relationships of Lamc1

• IL-1 beta increases laminin B2 chain mRNA levels and activates NF-kappa B in rat glomerular epithelial cells [8].

Other interactions of Lamc1

• Using an 850-base cDNA probe for the mouse laminin A-chain and a 1000-base cDNA probe for the mouse laminin B2 chain, we have screened mouse-Chinese hamster somatic cell hybrids in order to assign the genes for each of these polypeptides to their respective mouse chromosome [10].
• As a demonstration of the technique, a 5-cM, > 5 megabase contig was developed on the distal half of mouse Chromosome (Chr) 1, spanning the region from Lamb2 to At3 [11].
• These studies showed an increase in laminin B2 chain mRNA levels in GEC treated with IL-1 beta [8].

References