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Interaction of the protein nucleobindin with G αi2 , as revealed by the yeast two‐hybrid system
Author(s) -
Mochizuki Naoki,
Hibi Masahiko,
Kanai Yoshiyuki,
Insel Paul A.
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)01031-9
Subject(s) - yeast , chemistry , microbiology and biotechnology , two hybrid screening , biochemistry , biology
The heterotrimeric G protein, G αi2 , transduces signals from seven membrane spanning receptors to effectors such as adenylyl cyclase and ion channels. The purpose of this study was to identify these or other cellular proteins that interact with G αi2 by use of the yeast two‐hybrid system. A human B cell cDNA library was screened by this system using full length G αi2 . Four positive colonies were obtained. Two of the four were identified as nucleobindin, a calcium binding protein and a putative antigen to which anti‐nuclear antibodies are generated in mice with a disorder that resembles systemic lupus erythematosus. Nucleobindin has a leucine zipper, EF hands, and a signal peptide sequence and is thought to localize to the nucleus as well as being secreted. The specificity of intehraction between G αi2 and nucleobindin was confirmed by an in vitro binding assay using recombinant proteins. Transfection of G αi2 and nucleobindin in COS cells increased G αi2 expression relative to cells transfected with G αi2 and mock vector. Our results indicate that the yeast two‐hybrid system provides a means to identify novel proteins that interact with G α proteins. Nucleobindin appears to represent one of those proteins.