Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cell.2010.10.033 Byline: Liat Harel-Sharvit (1), Naama Eldad (1), Gal Haimovich (1), Oren Barkai (1), Lea Duek (1), Mordechai Choder (1) Keywords: RNA; CELLBIO Abstract: Little is known about crosstalk between the eukaryotic transcription and translation machineries that operate in different cell compartments. The yeast proteins Rpb4p and Rpb7p represent one such link as they form a heterodimer that shuttles between the nucleus, where it functions in transcription, and the cytoplasm, where it functions in the major mRNA decay pathways. Here we show that the Rpb4/7 heterodimer interacts physically and functionally with components of the translation initiation factor 3 (eIF3), and is required for efficient translation initiation. Efficient translation in the cytoplasm depends on association of Rpb4/7 with RNA polymerase II (Pol II) in the nucleus, leading to a model in which Pol II remotely controls translation. Hence, like in prokaryotes, the eukaryotic translation is coupled to transcription. We propose that Rpb4/7, through its interactions at each step in the mRNA lifecycle, represents a class of factors, 'mRNA coordinators,' which integrate the various stages of gene expression into a system. Author Affiliation: (1) Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 31096, Israel Article History: Received 17 December 2009; Revised 28 July 2010; Accepted 25 October 2010 Article Note: (miscellaneous) Published: November 11, 2010

The BH3-only BID protein partially localizes to the nucleus in healthy cells, is important for apoptosis induced by DNA damage, and is phosphorylated following induction of double-strand breaks in DNA. Results implicate BID as an ATM effector and raise the possibility that proapoptotic BID might also play a prosurvival role for S phase arrest.

It was already suggested in the early ‘70's that RNA molecules might transfer between mammalian cells in culture. Yet, more direct evidence for RNA transfer in animal and plant cells was only provided decades later, as this field became established. In this mini-review, we will describe evidence for the transfer of different types of RNA between cells through tunneling nanotubes (TNTs). TNTs are long, yet thin, open-ended cellular protrusions that are structurally distinct from filopodia. TNTs connect cells and can transfer many types of cargo, including small molecules, proteins, vesicles, pathogens, and organelles. Recent work has shown that TNTs can also transfer mRNAs, viral RNAs and non-coding RNAs. Here, we will review the evidence for TNT-mediated RNA transfer, discuss the technical challenges in this field, and conjecture about the possible significance of this pathway in health and disease. [ABSTRACT FROM AUTHOR]

A study was conducted to determine if RNA polymerase II core enzyme (Pol II) controls mRNA decay by recruiting yeast Rpb4/7, a nucleo-cytoplasmic shuttling heterodimer. The results showed Pol II not only mediated transcription, but also mRNA decay by recruiting Ppb4/7.

The spatial regulation of protein translation is an efficient way to create functional and structural asymmetries in cells. Recent research has furthered our understanding of how individual cells spatially organize protein synthesis, by applying innovative technology to characterize the relationship between mRNAs and their regulatory proteins, single-mRNA trafficking dynamics, physiological effects of abrogating mRNA localization in vivo and for endogenous mRNA labelling. The implementation of new imaging technologies has yielded valuable information on mRNA localization, for example, by observing single molecules in tissues. The emerging movements and localization patterns of mRNAs in morphologically distinct unicellular organisms and in neurons have illuminated shared and specialized mechanisms of mRNA localization, and this information is complemented by transgenic and biochemical techniques that reveal the biological consequences of mRNA mislocalization. [ABSTRACT FROM AUTHOR]