A comparative analysis of cDNA-derived sequences for rat and mouse beta 3 integrins (GPIIIA) with their human counterpart.
Alpha IIb beta 3 (GPIIb-IIIa), the platelet receptor for fibrinogen, is a member of the integrin superfamily. We have now cloned the mouse and rat beta 3 cDNAs. These data represent the first available non-human beta 3 sequences, allowing important comparative analyses. Both beta 3 sequences are highly homologous with human beta 3, well above average rodent-human protein homology of 79%. The ligand binding domains (aa) 109-171 and 204-229) are, respectively, 90% and 100% homologous. The beta 3 transmembrane and the cytoplasmic tail are surprisingly highly conserved, being 97% and 100% homologous, respectively, but share little homology with beta 1, or beta 2. This latter difference argues strongly in favor for a crucial beta 3-specific function for these domains. In conclusion, we present the first comparative analysis of beta 3 chains and demonstrate high overall homology. The biological implications of these comparisons are discussed.
U348 INSERM, Hôpital Lariboisière, Paris, France.
A M
AM
Cieutat
J P
JP
Rosa
F
F
Letourneur
M
M
Poncz
S
S
Rifat
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004247:DNA / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D009838:Oligodeoxyribonucleotides; D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D004247:DNA