Abstract
Cell polarity and morphogenesis are regulated by the small GTPase Cdc42. Even though major advances have been done in the field during the last years, the molecular details leading to its activation in particular cellular contexts are not completely understood. In fission yeast, the β(1,3)-glucanase Eng2 is a “moonlighting protein” with a dual function, acting as a hydrolase during spore dehiscence, and as component of the endocytic machinery in vegetative cells. Here, we report that Eng2 plays a role in Cdc42 activation during polarized growth through its interaction with the scaffold protein Scd2, which brings Cdc42 together with its guanine nucleotide exchange factor (GEF) Scd1. eng2Δ mutant cells have defects in activation of the bipolar growth (NETO), remaining monopolar during all the cell cycle. In the absence of Eng2 the accumulation of Scd1 and Scd2 at the poles is reduced, the levels of Cdc42 activation decrease, and the Cdc42 oscillatory behavior, associated with bipolar growth in wild type cells, is altered. Furthermore, overexpression of Eng2 partially rescues the growth and polarity defects of a cdc42-L160S mutant. Altogether, our work unveils a new factor regulating the activity of Cdc42, which could potentially link the polarity and endocytic machineries.
Highlights
Cell polarity and morphogenesis are regulated by the small GTPase Cdc[42]
Polarized growth is essential for morphogenesis and completion of a correct developmental program in eukaryotic organisms reviewed in Refs.[1,2,3,4,5]
We have found that Eng[2] interacts with the Cdc[42] scaffold protein Scd[2], and that depletion of Eng[2] causes a reduction in the tip accumulation of Scd[2] and the Cdc[42] guanine nucleotide exchange factor (GEF) Scd[1]
Summary
Cell polarity and morphogenesis are regulated by the small GTPase Cdc[42]. Even though major advances have been done in the field during the last years, the molecular details leading to its activation in particular cellular contexts are not completely understood. We report that Eng[2] plays a role in Cdc[42] activation during polarized growth through its interaction with the scaffold protein Scd[2], which brings Cdc[42] together with its guanine nucleotide exchange factor (GEF) Scd. Eng2Δ mutant cells have defects in activation of the bipolar growth (NETO), remaining monopolar during all the cell cycle. Cdc[42] is a key element in the regulation of polarized growth in eukaryotic cells reviewed in Refs.[2,20,21]. This small GTPase is essential for viability in S. pombe. In eng2Δ cells, endocytosis is blocked at high temperature and cells show growth defects and rounded morphology, indicative of a defect in polarity establishment or maintenance 49
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
