First Author | Kotaja N | Year | 2006 |
Journal | J Cell Sci | Volume | 119 |
Issue | Pt 13 | Pages | 2819-25 |
PubMed ID | 16787948 | Mgi Jnum | J:110342 |
Mgi Id | MGI:3640041 | Doi | 10.1242/jcs.03022 |
Citation | Kotaja N, et al. (2006) Interplay of PIWI/Argonaute protein MIWI and kinesin KIF17b in chromatoid bodies of male germ cells. J Cell Sci 119(Pt 13):2819-25 |
abstractText | Chromatoid bodies are thought to act as male-germ-cell-specific platforms for the storing and processing of haploid transcripts. The molecular mechanisms governing the formation and function of these germ-cell-specific structures have remained elusive. In this study, we show that the kinesin motor protein KIF17b, which is involved in the nucleocytoplasmic transport of RNA and of a transcriptional coactivator, localizes in chromatoid bodies. The chromatoid body moves actively and non-randomly in the cytoplasm of round spermatids, making frequent contacts with the nuclear envelope. The localization of KIF17b thereby offers a potential mechanism for microtubule-dependent mobility of chromatoid bodies, as well as for the transport of the specific components in and out of the chromatoid body. Interestingly, we demonstrate that KIF17b physically interacts with a testis-specific member of the PIWI/Argonaute family, MIWI, a component of chromatoid bodies implicated in RNA metabolism. A functional interplay between KIF17b and MIWI might be needed for the loading of haploid RNAs in the chromatoid body. Importantly, chromatoid bodies from round spermatids of miwi-null mice are not fully compacted and remain as a diffuse chromatoid material, revealing the essential role played by MIWI in the formation of chromatoid bodies. These results shed new light on the function of chromatoid bodies in the post-transcriptional regulation of gene expression in haploid germ cells. |