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Site-specific phosphorylations of the Arf activator GBF1 differentially regulate GBF1 function in Golgi homeostasis and secretion versus cytokinesis.
Walton, Kendall; Nawara, Tomasz J; Angermeier, Allyson R; Rosengrant, Hadley; Lee, Eunjoo; Wynn, Bridge; Victorova, Ekaterina; Belov, George; Sztul, Elizabeth.
Affiliation
  • Walton K; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA. kwalton1@uab.edu.
  • Nawara TJ; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
  • Angermeier AR; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
  • Rosengrant H; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
  • Lee E; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
  • Wynn B; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
  • Victorova E; Department of Veterinary Medicine, Virginia-Maryland College of Veterinary Medicine, University of Maryland, College Park, MD, 20742, USA.
  • Belov G; Department of Veterinary Medicine, Virginia-Maryland College of Veterinary Medicine, University of Maryland, College Park, MD, 20742, USA.
  • Sztul E; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1918 University Boulevard, MCLM 668, Birmingham, AL, 35233-2008, USA.
Sci Rep ; 13(1): 13609, 2023 08 21.
Article in En | MEDLINE | ID: mdl-37604968
Diverse cellular processes, including membrane traffic, lipid homeostasis, cytokinesis, mitochondrial positioning, and cell motility are critically dependent on the Sec7 domain guanine nucleotide exchange factor GBF1. Yet, how the participation of GBF1 in a particular cellular function is regulated is unknown. Here, we show that the phosphorylation of specific highly conserved serine and tyrosine residues within the N-terminal domain of GBF1 differentially regulates its function in maintaining Golgi homeostasis and facilitating secretion versus its role in cytokinesis. Specifically, GBF1 mutants containing single amino acid substitutions that mimic a stably phosphorylated S233, S371, Y377, and Y515 or the S233A mutant that can't be phosphorylated are fully able to maintain Golgi architecture and support cargo traffic through the secretory pathway when assessed in multiple functional assays. However, the same mutants cause multi-nucleation when expressed in cells, and appear to inhibit the progression through mitosis and the resolution of cytokinetic bridges. Thus, GBF1 participates in distinct interactive networks when mediating Golgi homeostasis and secretion versus facilitating cytokinesis, and GBF1 integration into such networks is differentially regulated by the phosphorylation of specific GBF1 residues.
Subject(s)

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Cytokinesis / Golgi Apparatus Language: En Journal: Sci Rep Year: 2023 Document type: Article Affiliation country: United States Country of publication: United kingdom

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Cytokinesis / Golgi Apparatus Language: En Journal: Sci Rep Year: 2023 Document type: Article Affiliation country: United States Country of publication: United kingdom