Structural highlights
Function
[OSKA_DROME] Organizes the germ plasm and directs localization of the posterior determinant nanos. Oskar protein is required to keep nos RNA and staufen protein at the posterior pole.[1] [2] [3]
Publication Abstract from PubMed
Oskar (Osk) protein plays critical roles during Drosophila germ cell development, yet its functions in germ-line formation and body patterning remain poorly understood. This situation contrasts sharply with the vast knowledge about the function and mechanism of osk mRNA localization. Osk is predicted to have an N-terminal LOTUS domain (Osk-N), which has been suggested to bind RNA, and a C-terminal hydrolase-like domain (Osk-C) of unknown function. Here, we report the crystal structures of Osk-N and Osk-C. Osk-N shows a homodimer of winged-helix-fold modules, but without detectable RNA-binding activity. Osk-C has a lipase-fold structure but lacks critical catalytic residues at the putative active site. Surprisingly, we found that Osk-C binds the 3'UTRs of osk and nanos mRNA in vitro. Mutational studies identified a region of Osk-C important for mRNA binding. These results suggest possible functions of Osk in the regulation of stability, regulation of translation, and localization of relevant mRNAs through direct interaction with their 3'UTRs, and provide structural insights into a novel protein-RNA interaction motif involving a hydrolase-related domain.
Structure of Drosophila Oskar reveals a novel RNA binding protein.,Yang N, Yu Z, Hu M, Wang M, Lehmann R, Xu RM Proc Natl Acad Sci U S A. 2015 Sep 15;112(37):11541-6. doi:, 10.1073/pnas.1515568112. Epub 2015 Aug 31. PMID:26324911[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Ephrussi A, Lehmann R. Induction of germ cell formation by oskar. Nature. 1992 Jul 30;358(6385):387-92. PMID:1641021 doi:http://dx.doi.org/10.1038/358387a0
- ↑ Kim-Ha J, Smith JL, Macdonald PM. oskar mRNA is localized to the posterior pole of the Drosophila oocyte. Cell. 1991 Jul 12;66(1):23-35. PMID:2070416
- ↑ Ephrussi A, Dickinson LK, Lehmann R. Oskar organizes the germ plasm and directs localization of the posterior determinant nanos. Cell. 1991 Jul 12;66(1):37-50. PMID:2070417
- ↑ Yang N, Yu Z, Hu M, Wang M, Lehmann R, Xu RM. Structure of Drosophila Oskar reveals a novel RNA binding protein. Proc Natl Acad Sci U S A. 2015 Sep 15;112(37):11541-6. doi:, 10.1073/pnas.1515568112. Epub 2015 Aug 31. PMID:26324911 doi:http://dx.doi.org/10.1073/pnas.1515568112
