Yolanda Sánchez Martín

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.

Group members
Yolanda Sánchez Martín Associate Professor (USAL)
Sofia Muñoz Feliz PhD Student
Elvira Manjón Pérez PhD Student
Recent publications
Muñoz S, Manjón E and Sánchez Y (2014)
The putative exchange factor Gef3p interacts with Rho3p GTPase and the septin ring during cytokinesis in fission yeast.
J Biol Chem. 289: 21995-22007
Muñoz S, Manjón E, García P, Sunnerhagen P and Sánchez Y (2014)
The checkpoint-dependent nuclear accumulation of Rho1p exchange factor Rgf1p is important for tolerance to chronic replication stress
Mol. Biol. Cell. 25: 1137-1150
This article was published online ahead of print in MBoC in Press (http://www.molbiolcell.org/cgi/doi/10.1091/mbc.E13-11-0689).
Cruz S, Muñoz S, Manjón E, García P and Sánchez, Y (2013)
Fission yeast cell wall sensor-like proteins Mtl2 and Wsc1 act turning on the GTPases Rho1p but independently of the cell wall integrity pathway
Microbiology Open 2: 778-794
Roncero C and Sánchez Y (2010)
Cell separation and the maintenance of cell integrity during cytokinesis in yeast: the assembly of a septum
Yeast  27: 521-530
García P, García I, Marcos F, Ruiz De Garibay G and Sánchez Y (2009)
Fission yeast Rgf2p is a Rho1p guanine nucleotide exchange factor required for spore wall maturation and for the maintenance of cell integrity in the absence of Rgf1p
Genetics 181: 1321-1334
Research grants
MINECO: BFU2011-24683
Links of interest