First published online December 31, 2003
Journal of Cell Science 117, 305e (2004)
© The Company of Biologists Limited
Modelling membranes for meiosis
During sporulation in yeast, a diploid mother cell divides meiotically to generate four haploid spores. Each of these must be surrounded by a forespore membrane (FSM), which the cell generates de novo within its cytoplasm. In a Commentary on p. 389, Chikashi Shimoda, discusses recent work showing that FSM formation is coordinated by spindle pole bodies (SPBs) the yeast version of centrosomes. These recruit novel components such as Mpc54 to their outer plaques during the second meiotic division, which initiate FSM formation. GFP tagging of the FSM proteins Spo3 and Psy1 has allowed researchers to trace the FSM as it extends out from the SPBs to envelope each haploid nucleus. Spo3 is a novel potential membrane protein, whereas Psy1 is a homologue of the mammalian protein syntaxin 1A, a component of the SNARE complexes that drive vesicle docking/fusion. Indeed, homologues of several SNARE proteins are implicated in sporulation, including synaptobrevin and SNAP25, which indicates that vesicle fusion drives FSM assembly. Given this machinery, Shimoda suggests that FSM formation provides a general model for regulation of membrane trafficking by microtubule-organizing centres, which could be applicable to other examples of de novo membrane formation, such as Drosophila embryo cellularization.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
Related articles in JCS:
- Forespore membrane assembly in yeast: coordinating SPBs and membrane trafficking
- Chikashi Shimoda
JCS 2004 117: 389-396.
[Abstract]
[Full Text]