First published online February 22, 2008
Development 135, 604e (2008)
© The Company of Biologists Limited
Oskar: anchoring germ plasm via endocytosis
The intracellular localization of RNAs and proteins often determines cell
fates. In developing Drosophila oocytes, the posterior pole
localization of oskar (osk) RNA (which requires a polarized
microtubule array) and Osk protein directs the assembly and anchoring of the
germ plasm at the posterior cortex. The germ plasm is where the factors
required for germline and abdomen formation (for example, the RNA helicase
Vasa) accumulate. Now, on p.
1107, Tanaka and Nakamura report that the endocytic pathway acts
downstream of Osk in Drosophila germ plasm assembly. By screening for
mutants in which Vasa accumulation was disrupted, they discover that germ
plasm assembly requires the endocytic pathway protein Rabenosyn-5 (Rbsn-5).
rbsn-5 mutant oocytes fail to maintain microtubule polarity, which
secondarily disrupts osk RNA localization. However, anteriorly
misexpressed Osk recruits Rbsn-5 and other endosomal proteins. The researchers
suggest that Osk localization at the posterior pole stimulates endosomal
cycling, which promotes the F-actin reorganization that anchors the germ plasm
components to the oocyte cortex.
Related articles in Development:
- The endocytic pathway acts downstream of Oskar in Drosophila germ plasm assembly
- Tsubasa Tanaka and Akira Nakamura
Development 2008 135: 1107-1117.
[Abstract]
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