The C-protein tetramer binds 230 to 240 nucleotides of pre-mRNA and nucleates the assembly of 40S heterogeneous nuclear ribonucleoprotein particles.

Huang, M., Rech, J. E., Northington, S. J., Flicker, P. F., Mayeda, A., Krainer, A. R., Lestourgeon, W. M. (January 1994) The C-protein tetramer binds 230 to 240 nucleotides of pre-mRNA and nucleates the assembly of 40S heterogeneous nuclear ribonucleoprotein particles. Molecular and Cellular Biology, 14 (1). pp. 518-533. ISSN 0270-7306

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Abstract

A series of in vitro protein-RNA binding studies using purified native (C1)3C2 and (A2)3B1 tetramers, total soluble heterogeneous nuclear ribonucleoprotein (hnRNP), and pre-mRNA molecules differing in length and sequence have revealed that a single C-protein tetramer has an RNA site size of 230 to 240 nucleotides (nt). Two tetramers bind twice this RNA length, and three tetramers fold monoparticle lengths of RNA (700 nt) into a unique 19S triangular complex. In the absence of this unique structure, the basic A- and B-group proteins bind RNA to form several different artifactual structures which are not present in preparations of native hnRNP and which do not function in hnRNP assembly. Three (A2)3B1 tetramers bind the 19S complex to form a 35S assembly intermediate. Following UV irradiation to immobilize the C proteins on the packaged RNA, the 19S triangular complex is recovered as a remnant structure from both native and reconstituted hnRNP particles. C protein-RNA complexes composed of three, six, or nine tetramers (one, two, or three triangular complexes) nucleate the stoichiometric assembly of monomer, dimer, and trimer hnRNP particles. The binding of C-protein tetramers to RNAs longer than 230 nt is through a self-cooperative combinatorial mode. RNA packaged in the 19S complex and in 40S hnRNP particles is efficiently spliced in vitro. These findings demonstrate that formation of the triangular C protein-RNA complex is an obligate first event in the in vitro and probably the in vivo assembly the 40S hnRNP core particle, and they provide insight into the mechanism through which the core proteins package 700-nt increments of RNA. These findings also demonstrate that unless excluded by other factors, the C proteins are likely to be located along the length of nascent transcripts.

Item Type: Paper
Uncontrolled Keywords: chemical cross-linking hnrnp proteins packaging proteins core proteins cdna cloning a1 gene complexes invitro domain identification
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing
bioinformatics > genomics and proteomics
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > nuclear ribonucleoprotein
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > pre-mRNA
CSHL Authors:
Communities: CSHL labs > Krainer lab
Depositing User: Matt Covey
Date: January 1994
Date Deposited: 11 Dec 2013 14:48
Last Modified: 11 Dec 2013 14:48
PMCID: PMC358402
Related URLs:
URI: https://repository.cshl.edu/id/eprint/28950

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