The γ‐subunit of the principal G‐protein from squid (Loligo forbesi) photoreceptors contains a novel N‐terminal sequence

FEBS Letters

Carne, Alan¹  Ryba, Nicholas J.P.¹  Lott, J.Shaun¹  Pottinger, John D.D.¹  Keen, Jeffrey N.¹  Findlay, John B.C.¹ 

[1] Department of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK

关键词: Invertebrate vision;    Molecular cloning;    G-protein subunit;    Loligo forbesi;    G-protein;    GTP-binding protein;    PLC;    phospholipase C;    SML;    sucrose monolaurate;    PCR;    polymerase chain reaction;    SSC;    150 mM NaCl;    15 mM sodium citrate;    pH 7;    NET;    15 mM Tris-Cl;    1 mM EDTA;    pH 8.3;    SSPE;    150 mM NaCl;    10 mM NaH2PO4;    1 mM EDTA;    pH 7.4;   

DOI  :  10.1016/0014-5793(92)80943-B

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The squid (Loligo forbesi) visual system presents as accessible a system for study of G-protein mediated signal transduction as the vertebrate rod outer segment with the added advantage that the major G-protein is a member of the Gq-class. Here the cDNA clone encoding the γ-subunit of this G-protein is reported, thereby completing the molecular cloning of the heterotrimeric G-protein. The deduced protein structure of G-γ has relatively little sequence identity with known mammalian counterparts particularly in comparison with the relatively high degree found for both the α- and β-subunits of this protein. In particular, the N-terminus of the squid visual G-γ contains a repetitive, highly charged region, rich in lysine and glutamate, that has no parallel in other G-proteins. The amino acid sequence of a number of peptides derived by chemical cleavage of G-γ accounted for much of the protein sequence predicted from the cDNA, including the unusual N-terminal region.

【 授权许可】

Unknown