Document Type
Article
Publication Date
10-1-2021
Abstract
Heterotrimeric G proteins (αβγ) function at the cytoplasmic surface of a cell's plasma membrane to transduce extracellular signals into cellular responses. However, numerous studies indicate that G proteins also play noncanonical roles at unique intracellular locations. Previous work has established that G protein βγ subunits (Gβγ) regulate a signaling pathway on the cytoplasmic surface of Golgi membranes that controls the exit of select protein cargo. Now, we demonstrate a novel role for Gβγ in regulating mitotic Golgi fragmentation, a key checkpoint of the cell cycle that occurs in the late G2 phase. We show that small interfering RNA-mediated depletion of Gβ1 and Gβ2 in synchronized cells causes a decrease in the number of cells with fragmented Golgi in late G2 and a delay of entry into mitosis and progression through G2/M. We also demonstrate that during G2/M Gβγ acts upstream of protein kinase D and regulates the phosphorylation of the Golgi structural protein GRASP55. Expression of Golgi-targeted GRK2ct, a Gβγ-sequestering protein used to inhibit Gβγ signaling, also causes a decrease in Golgi fragmentation and a delay in mitotic progression. These results highlight a novel role for Gβγ in regulation of Golgi structure.
Recommended Citation
Rajanala, Kalpana; Klayman, Lauren M.; and Wedegaertner, Philip B., "Gβγ regulates mitotic Golgi fragmentation and G2/M cell cycle progression." (2021). Department of Biochemistry and Molecular Biology Faculty Papers. Paper 196.
https://jdc.jefferson.edu/bmpfp/196
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
PubMed ID
34260268
Language
English
Comments
This article is the authors’ final published version in Molecular Biology of the Cell, Volume 32, Issue 20, October 2021, Article number 32:br2.
The published version is available at https://doi.org/10.1091/mbc.E21-04-0175. Copyright © Rajanala et al.