The International Journal of Developmental Biology

Int. J. Dev. Biol. 48: 1065 - 1077 (2004)

https://doi.org/10.1387/ijdb.041893ki

Vol 48, Issue 10

Rasputin, more promiscuous than ever: a review of G3BP

Review | Published: 1 December 2004

Katharine Irvine1, Renee Stirling2, David Hume1 and Derek Kennedy*,2

1Institute for Molecular Bioscience, University of Queensland, St Lucia, Australia and 2Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, Australia

Abstract

In this review, we highlight what G3BP's domain structure initially suggested; that G3BPs are "scaffolding" proteins linking signal transduction to RNA metabolism. Whilst it is most attractive to hypothesise about G3BP's role in signalling to mRNA metabolism, it is not known whether all G3BP functions impinge on their RNA-binding activities, so any theories are naturally subject to this qualification. It is hypothesised that, in coordination with an array of other proteins, G3BP, in a phosphorylation-dependent manner, is involved in the post-transcriptional regulation of a subset of mRNAs, at least some of which are in common with those regulated by Hu proteins. These transcripts, partially controlled at the post-transcriptional level by G3BPs, code for proteins important in transcription (e.g. c-Myc) and cytoskeletal arrangement (e.g. Tau), amongst other as yet undetermined pathways. The subtle differences between G3BP family members could dictate binding to a variety of signalling proteins, so each of the G3BPs may participate in different, though possibly related mRNPs, which are assembled in response to different stimuli. The combinatorial nature of the mRNP complex offers a powerful means of regulating gene expression, beyond that provided by a simple mRNA sequence. The ways in which mRNP flexibility and specificity may be harnessed to coordinate gene expression of functionally or structurally related mRNAs are not yet fully appreciated. Characterising mRNP composition and the function/s of mRNP components, such as the G3BPs, will aid in the understanding of how post-transcriptional mechanisms contribute to the global regulation of gene expression.

Keywords

G3BP, Rasputin, Bre5, RNA-binding protein

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