NSF Award
9985627
King<br/>9985627<br/><br/>RNA localization is a powerful strategy that can be used to localize<br/>proteins to subcellular domains and to control protein synthesis regionally. In<br/>germ cells, RNA targeting has profound implications for development, setting up local<br/>concentrations of regulatory proteins that establish regional fates in the developing embryo. The cellular mechanisms that select and transport RNAs are likely to be conserved, even across widely disparate species. In fact, it has been shown that yeast localizes RNA encoding cell-fate determinants to the distal tip of daughter buds, suggesting this mechanism is ancient . Recent evidence suggests that selection for transport may be initiated in the nucleus. However, with few exceptions, the identities of the interacting proteins involved in RNA selection, translational regulation and cortical<br/>anchoring are unknown. Understanding how RNAs are localized represents a central problem in both cell and developmental biology.<br/><br/>In order to study the mechanism of RNA localization, Dr. King has isolated and characterized seven mRNAs localized to the vegetal cortex of Xenopus oocytes. Two localization pathways were identified that operate during oogenesis to target RNAs to the vegetal cortex. Based on the identities of these seven RNAs, Dr. King has suggested that the early pathway evolved to specifically localize germ cell determinants whereas the late pathway serves to localize RNAs involved in embryonic development. This proposal will focus on analyzing an RNA, that is a member of the early pathway and a component of the germinal granules (13, 19, 23, 55) as well as VegT RNA, a representative of the late pathway. VegT encodes a transcription factor that plays an essential role in patterning the three primary germ layers in the embryo.<br/><br/>Controlling when and where genes are expressed is essential for the development of multicellular organisms. One strategy is to transcribe the DNA to RNA which is then localized. Later translation of this RNA into protein begins appropriate cell differentiation. Dr. Kings work will focus on how this mechanism maybe utilized to establish three tissue layers in the vertebrate embryo.
