NCBI Summary:
Sm-like proteins were identified in a variety of organisms based on sequence homology with the Sm protein family (see SNRPD2; 601061). Sm-like proteins contain the Sm sequence motif, which consists of 2 regions separated by a linker of variable length that folds as a loop. The Sm-like proteins are thought to form a stable heteromer present in tri-snRNP particles, which are important for pre-mRNA splicing.[supplied by OMIM]
Dcp1-Bodies in Mouse Oocytes. Swetloff A et al. Monitoring Editor: A. Gregory Matera Processing bodies (P-bodies) are cytoplasmic granules involved in the storage and degradation of mRNAs. In somatic cells, their formation involves miRNA-mediated mRNA silencing. Many P-body protein components are also found in germ cell granules, such as in mammalian spermatocytes. In fully grown mammalian oocytes, where changes in gene expression depend entirely on translational control, RNA granules have not as yet been characterized. Here we show the presence of P-body-like foci in mouse oocytes, as revealed by the presence of Dcp1a and the colocalization of RNA associated protein 55 (RAP55) and the DEAD box RNA helicase Rck/p54, two proteins associated with P-bodies and translational control. These P-body like structures have been called Dcp1-bodies and in meiotically-arrested primary oocytes, two types can be distinguished based upon their size. They also have different protein partners and sensitivities to the depletion of endogenous siRNA/miRNA and translational inhibitors. However, both type progressively disappear during in vitro meiotic maturation, and are virtually absent in metaphase II-arrested secondary oocytes. Moreover, this disassembly of hDcp1a-bodies is concomitant with the post-translational modification of EGFP-hDcp1a.
Follicle stages
Comment
Identification of zRAP55,a gene preponderantly expressed in Stages I and II oocytes of zebrafish. Zhao CL et al. In an in silico search for gonand specific expressed genes, we have identified zRAP55 which is enriched in the ovary of zebrafish . zRAP55 encodes a protein of 382 amino acids with a highly conserved Lsm domain. zRAP55 protein shares more than 56% identities with that of other vertebrate species. RT-PCR results show that it is predominantly expressed in the ovary. In situ hybridization and immunohistochemistry studies reveal that zRAP55 is ubiquitously dispersed throughout the cytoplasm of stages I and II oocytes, whereas no expression is observed in stages III and IV oocytes. As an RNA associated protein, zRAP55 might function in the control of protein translation at the early stages of oogenesis in zebrafish.