title: Rewiring Mid1p-independent medial division in fission yeast.
abstract: Correct positioning of the cell division machinery is key to genome stability. Schizosaccharomyces pombe is an attractive organism to study cytokinesis as it, like higher eukaryotes, divides using a contractile actomyosin ring. In S. pombe, many actomyosin ring components assemble at the medial cortex into node-like structures before coalescing into a ring [1, 2]. Assembly of cytokinetic nodes requires Mid1p, which recruits IQGAP-related Rng2p to the division site, after which other node components accumulate at the division site in a characteristic sequence [3-6]. How cytokinetic nodes assemble, whether the order of assembly of ring components is important, and whether Mid1p solely participates in ring positioning are poorly understood. Here, we show that synthetic targeting of IQGAP-related Rng2p, formin-Cdc12p, and myosin II (Myo2p) restores medial division in mid1 mutants, suggesting that ring proteins need not assemble at the division site in an invariant order. Unlike in wild-type cells, actomyosin rings in cells rewired to divide medially in the absence of Mid1p assemble late in anaphase. Furthermore, the rewiring process affects the ability of the actomyosin ring to track the nucleus upon perturbation of nuclear position. Our work reveals the power of synthetic rewiring studies in deciphering roles performed by multifunctional proteins.
authors.affiliation: Department of Biological Sciences, The National University of Singapore, 1 Research Link, Singapore 117604, Republic of Singapore.
authors.forename: Evelyn Yaqiong
authors.initials: EY
authors.lastname: Tao
authors.affiliation: Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604, Republic of Singapore.
authors.forename: Meredith
authors.initials: M
authors.lastname: Calvert
authors.affiliation: Department of Biological Sciences, The National University of Singapore, 1 Research Link, Singapore 117604, Republic of Singapore; Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604, Republic of Singapore; Mechanobiology Institute, The National University of Singapore, 1 Research Link, Singapore 117604, Republic of Singapore; Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK. Electronic address: m.k.balasubramanian@warwick.ac.uk.
authors.forename: Mohan K
authors.initials: MK
authors.lastname: Balasubramanian
mesh_terms: D048749:Cytokinesis; D016133:Polymerase Chain Reaction; D012568:Schizosaccharomyces / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C489694:Mid1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins