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AgSwe1p regulates mitosis in response to morphogenesis and nutrients in multinucleated Ashbya gossypii cells.

Publication ,  Journal Article
Helfer, H; Gladfelter, AS
Published in: Mol Biol Cell
October 2006

Nuclei in the filamentous, multinucleated fungus Ashbya gossypii divide asynchronously. We have investigated what internal and external signals spatially direct mitosis within these hyphal cells. Mitoses are most common near cortical septin rings found at growing tips and branchpoints. In septin mutants, mitoses are no longer concentrated at branchpoints, suggesting that the septin rings function to locally promote mitosis near new branches. Similarly, cells lacking AgSwe1p kinase (a Wee1 homologue), AgHsl1p (a Nim1-related kinase), and AgMih1p phosphatase (the Cdc25 homologue that likely counteracts AgSwe1p activity) also have mitoses distributed randomly in the hyphae as opposed to at branchpoints. Surprisingly, however, no phosphorylation of the CDK tyrosine 18 residue, the conserved substrate of Swe1p kinases, was detected in normally growing cells. In contrast, abundant CDK tyrosine phosphorylation was apparent in starving cells, resulting in diminished nuclear density. This starvation-induced CDK phosphorylation is AgSwe1p dependent, and overexpressed AgSwe1p is sufficient to delay nuclei even in rich nutrient conditions. In starving cells lacking septins or AgSwe1p negative regulators, the nuclear density is further diminished compared with wild type. We have generated a model in which AgSwe1p may regulate mitosis in response to cell intrinsic morphogenesis cues and external nutrient availability in multinucleated cells.

Duke Scholars

Published In

Mol Biol Cell

DOI

ISSN

1059-1524

Publication Date

October 2006

Volume

17

Issue

10

Start / End Page

4494 / 4512

Location

United States

Related Subject Headings

  • Phosphorylation
  • Morphogenesis
  • Models, Biological
  • Mitosis
  • Fungi
  • Fungal Proteins
  • Developmental Biology
  • Cell Nucleus
  • Cell Cycle Proteins
  • Cell Cycle
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Helfer, H., & Gladfelter, A. S. (2006). AgSwe1p regulates mitosis in response to morphogenesis and nutrients in multinucleated Ashbya gossypii cells. Mol Biol Cell, 17(10), 4494–4512. https://doi.org/10.1091/mbc.e06-03-0215
Helfer, Hanspeter, and Amy S. Gladfelter. “AgSwe1p regulates mitosis in response to morphogenesis and nutrients in multinucleated Ashbya gossypii cells.Mol Biol Cell 17, no. 10 (October 2006): 4494–4512. https://doi.org/10.1091/mbc.e06-03-0215.
Helfer, Hanspeter, and Amy S. Gladfelter. “AgSwe1p regulates mitosis in response to morphogenesis and nutrients in multinucleated Ashbya gossypii cells.Mol Biol Cell, vol. 17, no. 10, Oct. 2006, pp. 4494–512. Pubmed, doi:10.1091/mbc.e06-03-0215.

Published In

Mol Biol Cell

DOI

ISSN

1059-1524

Publication Date

October 2006

Volume

17

Issue

10

Start / End Page

4494 / 4512

Location

United States

Related Subject Headings

  • Phosphorylation
  • Morphogenesis
  • Models, Biological
  • Mitosis
  • Fungi
  • Fungal Proteins
  • Developmental Biology
  • Cell Nucleus
  • Cell Cycle Proteins
  • Cell Cycle