Importance of a myosin II-containing progenitor for actomyosin ring assembly in fission yeast.
An actomyosin-based contractile ring provides the forces necessary for cell cleavage in several organisms [1-3]. Myosin II is an essential component of the actomyosin ring and has also been detected as a "spot" in interphase Schizosaccharomyces pombe cells [4-5]. It is currently unknown if this myosin II-containing spot is important for cytokinesis. In this study, we characterize this myosin II-containing spot using a combination of genetic and cell biological analyses. Whereas myosin II at the actomyosin ring undergoes rapid turnover, myosin II at the spot does not. Maintenance of the myosin II-containing spot is independent of F-actin function. Interestingly, maintenance of this myosin II spot in interphase requires the function of Rng3p, a UCS domain-containing protein, the Caenorhabditis elegans homolog of which has recently been shown to be a cochaperone for myosin II assembly [6]. Disassembly of the spot in interphase prevents actomyosin ring formation in the subsequent mitosis, implying that the spot might represent a progenitor that is important for assembly of the actomyosin ring. Given that mitosis represents a short period of the fission yeast cell cycle, organization of this progenitor structure in interphase might ensure proper assembly of the actomyosin ring and successful cell division.
Wong
Kelvin C Y
KC
Cell Division Laboratory, Institute of Molecular Agrobiology, The National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
D'souza
Ventris M
VM
Naqvi
Naweed I
NI
Motegi
Fumio
F
Mabuchi
Issei
I
Balasubramanian
Mohan K
MK
D000205:Actomyosin / Q000378:metabolism*; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D007399:Interphase; D008856:Microscopy, Fluorescence; D009218:Myosins / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins
D003598:Cytoskeletal Proteins; C413223:Rng3 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D000205:Actomyosin; D009218:Myosins