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Mechanisms involved in the translocation of AGS3 from cell cortex to the Golgi apparatus following activation of a G‐protein coupled receptor
Author(s) -
Oner Sukru Sadik,
Lanier Stephen M
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.838.5
Subject(s) - microbiology and biotechnology , golgi apparatus , biology , receptor , signal transduction , guanine nucleotide exchange factor , phosphorylation , g protein , transport protein , biochemistry , endoplasmic reticulum
AGS3 and related GPR proteins provide unexpected regulatory mechanisms for G‐protein signaling systems, which are involved in diverse various cellular functions. The AGS3·Gαi signaling module is apparently regulated by cell surface, seven‐transmembrane receptors as well as non‐receptor guanine nucleotide exchange factors. Upon activation of a cell surface receptor, AGS3 dissociates from the cell cortex and apparently moves to the Golgi apparatus (GA). The mechanism of this translocation and the functional consequences are not defined and this report focuses on these questions. The receptor‐mediated movement of AGS3 to the GA required the TPR domain of AGS3. AGS3 constructs lacking S/T phosphorylation sites in the GPR domain or containing site‐directed mutations in the TPR domain known to alter AGS3 trafficking were effectively relocated to the GA following receptor activation. Co‐expression of the nonreceptor GEF Ric‐8A also disrupted the AGS3·Gαi signaling module, but did not increase the presence of AGS3 in the GA. Finally, receptor‐mediated movement of AGS3 to the GA altered the structural integrity of the GA as determined by immunofluorescence imaging of GA resident proteins. The regulated oscillation of AGS3 between the cell cortex and the Golgi apparatus offers unexpected mechanisms for modulating protein secretion and Golgi dynamics.