The human genome encodes at least three non‐allellic G proteins with αi‐type subunits

FEBS Letters

Codina, Juan¹  Abramowitz, Joel¹  Mattera, Rafael¹  Birnbaumer, Lutz¹  Suki, Wadi N.¹ 

[1] Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA

关键词: Pertussis toxin;    G protein;    Adenylyl cyclase;    Phospholipase C;    Phospholipase A2;    K+ channel;   

DOI  :  10.1016/0014-5793(87)80900-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The amino acid sequence and composition of α-subunits of signal transducing G proteins of the same kind appear to vary by no more than 2% from species to species. Here we isolated a human liver cDNA using an oligonucleotide complementary to the sequences encoding the pertussis toxin (PTX) ADP-ribosylation site of the α-subunit of the rat brain G protein called G_i. Its open reading frame characterizes it as an α_i-type cDNA—as opposed to α_o-type—but predicts an amino acid composition that differs by 7% and 14%, respectively, from two other human α_i-type molecules. Together with human brain α_i (type-1) and human monocyte α_i (type-2), the new human liver α_i cDNA (type-3) forms part of a family of α_i molecules. Type-3 α_i cDNA hybridizes to a ∼ 3.6 kilobase long mRNA and type-2 α_i cDNA hybridizes to an mRNA species of ∼ 2.7 kilobases. This indicates that the human genome has at least three non-allellic genes encoding non-α_o-type PTX substrates and provides structural evidence for the hypothesis that distinct effector systems are regulated by similar but nevertheless distinct PTX substrates.

【 授权许可】

Unknown