Abstract
Precise positioning of the cellular division plane is important for accurate segregation of genetic material and determination of daughter cell fates. Here we report a surprising connection between division site positioning and the organization of the cortical endoplasmic reticulum (ER). The cortical ER is an interconnected network of flat cisternae and highly curved tubules sharing a continuous lumen [1, 2]. Stabilization of high curvature by reticulon and DP1 family proteins contributes to formation of tubules [3-5]. We show that in the fission yeast Schizosaccharomyces pombe, the ER network is maintained by a set of three membrane proteins: reticulon/Rtn1p, DP1/Yop1p, and a newly identified evolutionarily conserved protein, Tts1p. Cells lacking the ER domain sustained by these proteins exhibit severe defects in division plane positioning as a result of abnormal dispersion of a key regulator of division site selection, Mid1p, along the cell cortex. This triggers delocalized assembly of actomyosin cables and compromises their compaction into a single medially positioned ring. We propose that the cortical ER network restricts the lateral motion of Midi p and hence generates a permissive zone for actomyosin ring assembly precisely at the cell equator.
Original language | English |
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Article number | N/A |
Pages (from-to) | 1029-1034 |
Number of pages | 6 |
Journal | Current Biology |
Volume | 20 |
Issue number | 11 |
DOIs | |
Publication status | Published - 8 Jun 2010 |
Keywords
- TUBULAR ENDOPLASMIC-RETICULUM
- CELL-DIVISION PLANE
- FISSION YEAST
- SCHIZOSACCHAROMYCES-POMBE
- MEMBRANE-PROTEINS
- CONTRACTILE RING
- MID1P
- GENE
- CYTOKINESIS
- SITE