Cell morphogenesis is a fundamental phenomenon that involves understanding a number of biological processes including the developmental program, polarity and cell division. Fission yeast sts5 mutant cells are round rather than cylindrical with cortical actin randomly dispersed. Genetic analyses demonstrate that the sts5+ gene is required for maintenance of cell shape during interphase when the cell normally exhibits polarised growth. The sts5 mutant is not defective in cell wall integrity. Deletion of ppe1+, which encodes a type 2A-like protein phosphatase, shows similar phenotypes to the sts5 mutant and these two mutations are synthetically lethal. Multicopy plasmids containing either the protein kinase C-like gene pck1+ or the protein tyrosine phosphatase pyp1+, an inhibitor of an osmosensing Sty1/Spc1 MAP-kinase, are capable of suppressing the sts5 mutation. Consistent with this, we have found that the wis1 mutation, which is defective in a MAP-kinase kinase of the pathway, suppresses the sts5 mutation. The predicted sts5+ gene product exhibits sequence similarity to two yeast proteins, Dis3 and Ssd1 and a nematode protein, F46E8.6, where the former two yeast proteins have been shown to be involved in cell cycle control and cell morphogenesis. The sts5+ gene is not essential for cell viability, but is absolutely required for polarised growth as the gene disruption showed the same phenotypes as those of the original mutants. Overexpression of the sts5+ gene resulted in altered cell morphology and, cortical actin in these overproducing cells was also abnormal, fainter and often dispersed. Anti-Sts5 antibody specifically detected a 130 kDa protein by western blotting. A green fluorescent protein-Sts5 fusion protein localised in the cytoplasm with a discrete punctate pattern, suggesting that the Sts5 protein is a component of a novel structure. These results have indicated that the Sts5 protein is a crucial determinant of polarised growth and that it functionally interacts with the serine/threonine phosphatase, protein kinase C, and an osmosensing MAP-kinase to maintain cell morphology.
Call for papers: Cell and Tissue Polarity
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We are welcoming submissions for our next special issue, which will focus on ‘Cell and tissue polarity’ and will be guest edited by David Bryant. Submission deadline: 15 July.
The Forest of Biologists
We are excited to announce the launch of The Forest of Biologists, a new biodiversity initiative created with support from the Woodland Trust, aiming to counteract nature loss and safeguard some of the most critically endangered ecosystems for future generations. For every Research Article and Review/Commentary article that is published in Journal of Cell Science, a native tree is planted in a forest in the UK. View our virtual forest here.
Propose a new Workshop for 2025
Do you have an idea for a Workshop? We are now accepting proposals for our 2025 Biologists Workshops programme. As the scientific organiser, your involvement will be focused on the science. We'll take care of all the logistics. In 2025 we'll continue our efforts to diversify our Workshop programme and will be reserving one of our Workshops for an application from a Global South (GS) country to host an event overseas.
Editorial: Publishing where it matters
Cell Scientists to Watch
As a community-focused journal, Journal of Cell Science is keen to support the next generation of cell biologists. Check out Cell Scientists to Watch, our interview series featuring talented researchers who have recently set up their own labs.
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