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Updated: May 24, 2026
12:19
Analysis of Cell Cycle Position in Mammalian Cells
Published on: January 21, 2012
Rab11-FIP3 is a cell cycle-regulated phosphoprotein
Louise L Collins1, Glenn Simon, Johanne Matheson
1Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
BMC Cell Biology
|March 10, 2012
Summary
Rab11-FIP3 (FIP3) phosphorylation is cell cycle regulated, with dephosphorylation occurring during telophase. While S102 phosphorylation impacts cytokinesis, other sites do not affect recycling endosome distribution.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Rab11 and its effector Rab11-FIP3 (FIP3) are involved in recycling endosome trafficking during cell division (cytokinesis).
- FIP3 also regulates recycling endosome distribution during interphase.
- The role of FIP3 phosphorylation in these cellular processes was investigated.
Purpose of the Study:
- To investigate the role of FIP3 phosphorylation in cell cycle regulation and recycling endosome trafficking.
- To identify specific phosphorylation sites on FIP3 and their functional significance.
Main Methods:
- Identification of FIP3 phosphorylation sites in vivo and in vitro using techniques like Cdk1-cyclin B assays.
- Site-directed mutagenesis to study the effect of phosphorylation site mutations on FIP3 function.
- Analysis of FIP3 localization and cell morphology (e.g., binucleate cell formation) under different conditions.
Main Results:
- Four in vivo phosphorylation sites (S-102, S-280, S-347, S-450) were identified, with S-102 being a target for Cdk1-cyclin B.
- S-102 phosphorylation occurs in metaphase and is reversed in telophase; its mutation to aspartate (S102D) increases binucleate cells.
- Mutations at other identified sites (S-280, S-347, S-450) and previously known sites did not affect cytokinesis or FIP3 distribution.
Conclusions:
- FIP3 is a cell cycle-regulated phosphoprotein, with dephosphorylation accompanying its membrane association during telophase.
- S102 dephosphorylation is linked to telophase, and its mutation has a minor impact on cytokinesis.
- The identified phosphorylation sites are not essential for the spatial control of recycling endosome distribution or function.
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