Localization of palmitoylated and activated G protein α‐subunit in Dictyostelium discoideum

Abstract

Guanine nucleotide-binding proteins (G proteins) act as molecular switches to regulate many fundamental cellular processes. The lipid modification, palmitoylation, can be considered as a key factor for proper G protein function and plasma membrane localization. In Dictyostelium discoidum, Gα2 is essential for the chemotactic response to cAMP in their developmental life cycle. However, the regulation of Gα2 with respect to palmitoylation, activation and Gβγ association is less clear. In this study, Gα2 is shown to be palmitoylated on Cys-4 by [ H]palmitate labeling. Loss of this palmitoylation site results in redistribution of Gα2 within the cell and poor D. discoideum development. Cellular re-localization is also observed for activated Gα2. In the membrane fraction, Gα2-wt (YFP) is highly enriched in a low-density membrane fraction, which is palmitoylation-dependent. Activated Gα2 monomer and heterotrimer are shifted to two different higher-density fractions. These results broaden our understanding of how G protein localization and function are regulated inside the cells.

Palmitoylation is required for Sept8‐204 and Sept5 to form vesicle‐like structure and colocalize with synaptophysin

“…and therefore participates in modulating diversified cellular and physiological functions. [3][4][5] Previously, it was reported that Sept8-204, a transcript of Sept8 that is exclusively expressed in neuron, is modified by palmitoylation both in vitro and in vivo, 6,7 yet, many aspects of Sept8-204 palmitoylation at molecular and cellular levels remain largely unknown and invite further investigations.…”

“…In general, dynamic protein palmitoylation may be involved in regulating protein subcellular localization, protein‐protein interaction, and signaling transduction and so forth. and therefore participates in modulating diversified cellular and physiological functions 3–5 . Previously, it was reported that Sept8‐204, a transcript of Sept8 that is exclusively expressed in neuron, is modified by palmitoylation both in vitro and in vivo, 6,7 yet, many aspects of Sept8‐204 palmitoylation at molecular and cellular levels remain largely unknown and invite further investigations.…”