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Generation of Gα i2 G184S conditional mutant mice to study regulator of G protein signaling (RGS) proteins
Author(s) -
Parra Sergio,
Huang Xinyan,
Wade Susan,
Kaur Kuljeet,
Charberneau Raelene,
Neubig Richard R
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1114.10
Subject(s) - regulator of g protein signaling , g protein , cre recombinase , mutant , biology , genetically modified mouse , transgene , microbiology and biotechnology , exon , wild type , muscarinic acetylcholine receptor , gq alpha subunit , gtpase activating protein , signal transduction , receptor , genetics , gene
GTPase activity of G inhibitory proteins (Gα i ) is strongly accelerated by RGS proteins. A mutant mouse (Gα i2 G184S ) in which RGS‐mediated negative regulation is lost shows protection against ex vivo cardiac ischemia‐reperfusion injury, and had worsened outcomes in two in vivo models of heart failure. However, such mice have a complex phenotype and decreased viability. In order to better define the mechanisms mediating these cardiovascular effects, we have developed a novel Gα i2 G184S conditional knock‐in mouse model with a loxP‐flanked minigene encoding wild‐type exons 5–9 in front of the mutant exon 5. We show that floxed‐allele‐ carrying mice appear normal and fertile. Upon crossing the Gα i2 G184S conditional to the Cre‐ER T2 transgenic mice, the wildtype sequence is efficiently deleted by Cre‐mediated excision in vivo after tamoxifen treatment and Gα i2 mRNA contains mostly mutant sequence. Levels of Gα i2 protein were somewhat reduced in several tissues, but responses to the stimulation of α2 and muscarinic M2 receptors were similar between Cre‐ER T2 /Gα i2 +/+ and Cre‐ER T2 /Gα i2 G184Scond/G184Scond mice before tamoxifen treatment. After tamoxifen treatment, Gα i2 mediated responses are enhanced in Cre‐ER T2 /Gα i2 G184Scond/G184Scond mice. This mouse model will be a valuable tool to dissect temporal and tissue‐specific roles of GPCRs, Gα i2 , and RGS proteins. (Supported by NIH R01 GM039561‐23)