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Elucidation of structural determinants of polycystin‐1 interaction with G α 12
Author(s) -
Snelson Mark Thomas,
Cavagnini Kyle S,
Denker Bradley M.,
Meigs Thomas E.
Publication year - 2013
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.27.1_supplement.598.4
Subject(s) - heterotrimeric g protein , pkd1 , cytoplasm , biology , amino acid , chemistry , microbiology and biotechnology , polycystic kidney disease , g protein , genetics , signal transduction , kidney
Autosomal dominant polycystic kidney disease is a widespread malady in which mutations in the cell surface protein polycystin‐1 (PC1) are found in nearly 85% of cases. PC1 interaction with the heterotrimeric G protein Gα12 has been implicated as a regulator of Gα12‐mediated events that include apoptosis. The C‐terminal, cytoplasmic tail of PC1 has been shown to interact with several G protein α‐subunits, and a 20 amino acid G protein binding sequence (GPS) resides within this cytoplasmic domain. Our previous work revealed a 74 amino acid region of the PC1 tail, encompassing the GPS, to be necessary for Gα12 binding. To identify specific PC1 residues involved in Gα12 interaction, we have engineered several single and multiple charge‐substitution mutations within the GPS. Co‐precipitation assays have revealed several PC1 residues as potential determinants of Gα12 binding. Furthermore, a truncation mutant of PC1 downstream of the GPS, previously linked to polycystic kidney disease, shows a near‐complete loss of Gα12 binding. Our findings from apoptosis assays and transcriptional activation assays suggest that direct interaction between PC1 and Gα12 is essential for the ability of PC1 to negatively regulate Gα12‐mediated signaling. We acknowledge support from the UNC‐Asheville Undergraduate Research Program (MTS and KSC), Harvard Polycystic Kidney Center (BMD), and Lineberger Comprehensive Cancer Center (TEM).