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Understanding Gα q/11 localization and trafficking in uveal melanoma
Author(s) -
Randolph Clinita,
Wedegaertner Philip
Publication year - 2018
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.2018.32.1_supplement.661.6
Subject(s) - palmitoylation , microbiology and biotechnology , signal transduction , phosphorylation , hek 293 cells , mapk/erk pathway , chemistry , subcellular localization , melanoma , nuclear localization sequence , biology , cytoplasm , cancer research , biochemistry , cysteine , receptor , enzyme
Constitutively activating mutations in Gα q and Gα 11 (Gα q/11 ) have been reported in up to 93% of uveal melanomas. Although constitutively active Gα q/11 promote uveal melanoma tumorigenesis through activation of multiple downstream pathways, no therapies inhibit constitutively active Gα q/11 . Studies suggest that upon activation of some Gα subunits increased palmitate turnover and increased cytoplasmic localization occur. The purpose of our studies is to understand the role of palmitoylation in trafficking and signaling of constitutively active Gα q/11 in uveal melanoma. Using live cell imaging and cellular fractionation of HEK 293 cells and uveal melanoma cells, constitutively active Gα q Q209L and Gα q Q209P show decreased localization at membranes compared to wild type Gα q , suggesting increased turnover of attached palmitate in constitutively active mutants. Moreover, immunofluorescence microscopy revealed that a palmitoylation‐deficient constitutively active mutant displays a complete loss of plasma membrane localization and an inability to signal as measured by Rho‐ and Rac‐dependent YAP translocation into the nucleus, TEAD‐dependent luciferase activity, and ERK phosphorylation. These studies demonstrate that palmitoylation of mutationally activated Gα q/11 is required for its signaling functions. Although live cell imaging and cellular fractionation experiments reveal decreased membrane localization of constitutively active Gα q compared to wild‐type Gα q , our studies suggest that complete loss of membrane localization abolishes constitutively active Gα q dependent signaling. Disruption of constitutively active Gα q/11 palmitoylation and localization may be an effective strategy for inhibiting constitutively active Gα q/11 oncogenic signaling in uveal melanoma. Support or Funding Information This research was funded by NIH grants R01GM056444‐16, R01GM056444‐16S1 (Research Supplements to Promote Diversity in Health‐Related Research) and T32 GM100836. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .