Henar Valdivieso

Vesicle trafficking and glucan síntesis in Schizosaccharomyces pombe

One of the most attractive fields in Biology is the knowledge of how organisms generate and keep a predestined shape. We use yeasts as model organisms to study morphogenesis because they are eukaryotic unicellular organisms. They have the advantage of developing all the morphogenetic processes in one single cell so the relationship between the morphogenetic controls and their effect in the organism can be analyzed easily. There are three morphogenetic events which cells must regulate tightly to guarantee their survival as organisms and, therefore, to ensure the propagation of their species: establishment of polarity, cytokynesis and sexual development.

Our goal is to study the role that the exocytosis and the endocytosis play in the regulation of morphogenesis in the fission yeast Schizosaccharomyces pombe; in particular, we are interested in deciphering the relationship between vesicle transport and the processes of cytokinesis, mating and response to stress. To achieve this goal we are studying the role of proteins from Schizosaccharomyces pombe that are similar to Saccharomyces cerevisiae proteins involved in the regulation of the synthesis of chitin, a polymer that has not been detected in S. pombe. We study the function of these proteins to unveil their general function, preserved along the evolution, which Saccharomyces has adapted to its need of synthesizing chitin.

The study of some of these proteins indicates that in S. pombe they are dedicated to the trafficking of the β(1,3) glucan synthase enzymes. β(1,3) glucan is an essential structural component of the fission yeast cell wall. At this moment, the group is developing several lines of research: one is centred in understanding how Cfh3 regulates the endocytosis of the β(1,3) glucan synthase Bgs1; for this purpose, the relationship between Cfh3p and clathrin and the AP2 complex is being analyzed. Another work line is dedicated to characterize the Cfr1/Csr1 complex, formed by two late-Golgi proteins that regulate the exit of β(1,3) glucan synthases from the endoplasmic reticulum and seems to participate in their quality control during secretion. Finally, we are studying the process of membrane fusion by means of the characterization of Dni1 and Dni2, a complex of complex of two proteins with similarity to claudins that are necessary for the cell fusion during mating.

Cellular distribution of the Saccharomyces cerevisiae Chs (from Chitin synthesis) and the Schizosaccharomyces pombe Chs-like proteins.

Group members
Henar Valdivieso Montero Associate Professor (USAL)
Mª Ángeles Curto Borrego Postdoc
Sandra Moro Román PhD Student
Francisco Yanguas Samaniego PhD Student
Carmen Gutiérrez González Technician
Recent publications
Hoya M, Yanguas F, Moro S, Prescianotto-Baschong C, Doncel C, de León N, Curto MÁ, Spang A, Valdivieso MH (2017)
Traffic Through the Trans-Golgi Network and the Endosomal System Requires Collaboration Between Exomer and Clathrin Adaptors in Fission Yeast
Genetics 205(2):673-690.
de León N, Hoya M, Curto MA, Moro S, Yanguas F, Doncel C, Valdivieso MH (2016)
The AP-2 complex is required for proper temporal and spatial dynamics of endocytic patches in fission yeast.
Mol Microbiol 100:409-424.
Curto MA, Sharifmoghadam MR, Calpena E, De León N, Hoya M, Doncel C, Leatherwood J, Valdivieso MH (2014)
Membrane organization and cell fusion during mating in fission yeast requires multipass membrane protein Prm1.
Genetics 196(4):1059-1076.
De León N, Sharifmoghadam MR, Hoya M, Curto MA, Doncel C, Valdivieso MH (2013)
Regulation of cell wall synthesis by the clathrin light chain is essential for viability in Schizosaccharomyces pombe
PLoS One 8:e71510.
Sharifmoghadam MR, Curto MA, Hoya M, De León N, Martin-Garcia R, Doncel C, Valdivieso MH (2012)
The integrity of the cytokinesis machinery under stress conditions requires the glucan synthase Bgs1p and its regulator Cfh3p
PLoS One 7:e42726.
Research grants
MINECO: BFU2013-48582-C2-2-P
Links of interest