A novel structural variant of the human beta 4 integrin cDNA.
The ability of the alpha 6 beta 4 integrin to function as a laminin receptor appears to be cell-type dependent. We reported that this integrin functions as a laminin receptor on clone A cells, a colon carcinoma cell line (Lee et al., J. Cell Biol., 117:671-678), but this integrin may not function as a laminin receptor on all cell types in which it is expressed. One potential mode of alpha 6 beta 4 regulation resides in the beta 4 cytoplasmic domain because structural variants of this domain exist. We isolated beta 4 clones from a clone A cDNA library and identified a 21 bp (7aa), in-frame deletion not previously reported. This 7aa variant is located within a region that exhibits a relatively high degree of homology (42%) with the 70aa insert previously reported by Tamura et al. (J. Cell Biol., 111:1593-1604). One major difference between these two regions is that the region we have highlighted does not contain the four potential serine/threonine phosphorylation sites that are present in the 210 bp (70aa) insert. PCR analysis revealed that the 7aa variant is also expressed in RNA obtained from normal colon and placenta.
Clarke
A S
AS
Laboratory of Cancer Biology, Deaconess Hospital, Harvard Medical School, Boston, MA 02115.
Lotz
M M
MM
Mercurio
A M
AM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002999:Clone Cells; D003106:Colon / Q000378:metabolism; D003110:Colonic Neoplasms; D017931:DNA Primers; D018076:DNA, Complementary; D005260:Female; D014644:Genetic Variation; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D039663:Integrin beta4; D016023:Integrins / Q000096:biosynthesis / Q000235:genetics*; D007413:Intestinal Mucosa / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010920:Placenta / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D014176:Protein Biosynthesis; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D018076:DNA, Complementary; D039663:Integrin beta4; D016023:Integrins