Molecular cloning of the cDNA encoding human laminin A chain.
Laminin is a large basement membrane glycoprotein composed of three subunits designated the A, B1, and B2. We report here the isolation and nucleotide sequence of human laminin A chain cDNA. The nucleotide sequence spans 9505 bases and has an open reading frame encoding 3075-amino acids. The sequence covers a 77-nucleotide long 5' untranslated region and a 190-nucleotide long 3' sequence in front of the poly (A)+ tail. In analogy with the mouse A chain sequence, the deduced human amino acid sequence contains eight-distinct domains of four-globular regions, three-cysteine-rich domains and an alpha-helical region, which is though to interact with the B chains of laminin. The deduced amino acid sequence is 14-amino acids shorter than the mouse A chain sequence. Seven of these amino acids are located in the putative signal sequence. The overall identity between the sequences from the two species is 78%. The carboxylterminal globular (G) domain contains five homologous subdomains characterized by a conserved seven-amino acid repeat within each subdomain. Both human and mouse A chain are about 39% identical to the G domain of merosin, a recently discovered A chain homologue. Unlike the mouse A chain, the human A chain contains a potential cell binding sequence (RGD) in this domain. The RGD sequence that is thought to be a cryptic cell attachment site in the amino-terminal domain IIIb of mouse laminin is not conserved in the human sequence.
Haaparanta
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La Jolla Cancer Research Foundation, CA 92037.
Uitto
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Ruoslahti
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Engvall
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D002822:Choriocarcinoma; D003001:Cloning, Molecular / Q000379:methods; D004247:DNA / Q000235:genetics; D005260:Female; D015723:Gene Library; D006801:Humans; D007797:Laminin / Q000235:genetics*; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011061:Poly A / Q000235:genetics; D011247:Pregnancy; D011487:Protein Conformation; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014594:Uterine Neoplasms
D007797:Laminin; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D004247:DNA