Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Full Text Full Text (PDF, 2379K) PDF+supp data (3820K) PPT slides of all figures Supplemental Material Index Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Björk, P. Articles by Wieslander, L. Search for Related Content PubMed PubMed Citation Articles by Björk, P. Articles by Wieslander, L. Pubmed/NCBI databases Substance via MeSH Social Bookmarking                            What's this?

Specific combinations of SR proteins associate with single pre-messenger RNAs in vivo and contribute different functions

¹ Department of Molecular Biology and Functional Genomics and ² Department of Mathematics, Stockholm University, SE-106 91 Stockholm, Sweden
³ Ludwig Institute for Cancer Research, SE-751 24 Uppsala, Sweden

Correspondence to Lars Wieslander: Lars.Wieslander{at}molbio.su.se

Serine/arginine-rich (SR) proteins are required for messenger RNA (mRNA) processing, export, surveillance, and translation. We show that in Chironomus tentans, nascent transcripts associate with multiple types of SR proteins in specific combinations. Alternative splicing factor (ASF)/SF2, SC35, 9G8, and hrp45/SRp55 are all present in Balbiani ring (BR) pre-messenger ribonucleoproteins (mRNPs) preferentially when introns appear in the pre-mRNA and when cotranscriptional splicing takes place. However, hrp45/SRp55 is distributed differently in the pre-mRNPs along the gene compared with ASF/SF2, SC35, and 9G8, suggesting functional differences. All four SR proteins are associated with the BR mRNPs during export to the cytoplasm. Interference with SC35 indicates that SC35 is important for the coordination of splicing, transcription, and 3' end processing and also for nucleocytoplasmic export. ASF/SF2 is associated with polyribosomes, whereas SC35, 9G8, and hrp45/SRp55 cosediment with monoribosomes. Thus, individual endogenous pre-mRNPs/mRNPs bind multiple types of SR proteins during transcription, and these SR proteins accompany the mRNA and play different roles during the gene expression pathway in vivo.

J. Zhao's present address is Cancer Center Karolinska, Dept. of Oncology and Pathology, Karolinska Institute, SE-171 77 Stockholm, Sweden.

O.P. Singh's present address is Centre for Environmental Studies, North-Eastern Hill University, Shillong 793 022, India.

Abbreviations used in this paper: ANOVA, analysis of variance; ASF, alternative splicing factor; BR, Balbiani ring; Ct-RSF, C. tentans repressor splicing factor; CTD, carboxy-terminal domain; hnRNP, heterogeneous nuclear RNP; mRNP, messenger RNP; NPC, nuclear pore complex; TAP, Tip-associated protein.

© 2009 Björk et al.
This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jcb.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).

CiteULike

Complore

Connotea

Del.icio.us

Digg

Facebook

Reddit

Technorati

Twitter

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents