Connections and directions among Rho1p-GEFs, morphogenesis and cells cycle in fission yeast

How cells attain their shape and size is one of the fundamental questions in Biology. Our lab studies molecular and biochemical mechanisms underlying the dynamic cellular processes responsible for morphogenesis in fission yeast. Our work is focused to understand the regulation of Guanine nucleotide-exchange factors (GEFs). GEFs are multidomain proteins directly responsible for the activation of Rho-family GTPases in response to extracellular stimuli (Fig.1).

We have characterized Rgf1p, Rgf2p and Rgf3p, the three Rho-GEFs proteins are activators of the Rho1p GTPase in S. pombe. Lack of the GEF proteins produces severe defects in cell integrity together with defects in cell polarity. Rgf1p is required for bipolar growth activation during NETO (New End Take OFF) (Fig.2). Rgf2p playsan essential role during the sporulation process and in vegetative cells functions together with Rgf1p while Rgf3p activates the Rho1p functions necessary to maintain cell integrity during septation. Previous work from our laboratory (in fission yeast) and from others, have demonstrated that a specific GEF regulates a subset of Rho1p functions, specifically linking the stimulus induced signalling to a particular response: cell wall synthesis, cytoskeletal remodeling, and secretion.

We are interested to know the role of Rho1p –GEFs in regulation of cytokinesis, cell polarity, dynamics of microtubules and actin. Recently we are studying whether the regulation of Rho-GEFs could be part of the mechanism that promotes survival in the presence of chronic replication stress. In our work, we use interdisciplinary approaches, combining the expertise and perspectives of cell biology, biochemistry and genetics.

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Group members

Yolanda Sánchez Martín Associate Professor (USAL)
Sofia Muñoz Feliz PhD Student
Elvira Manjón Pérez PhD Student

Contact

Yolanda Sánchez Martín ysm@usal.es
923294882
Laboratory 1.2

Research grants

MINECO BFU2011-24683