Prp24: Difference between revisions
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<StructureSection load='2ghp' size='450' side='right' scene='Sandbox_Reserved_340/2ghp/1' caption=''> | |||
'''Prp24''' ('''Pr'''e-mRNA splicing '''P'''rotein '''24''') is a [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae ''Saccharomyces cerevisiae''] yeast protein that functions in the formation of base pair interactions between the [http://en.wikipedia.org/wiki/U6_spliceosomal_RNA U6] and [http://en.wikipedia.org/wiki/U4_spliceosomal_RNA U4] [http://en.wikipedia.org/wiki/SnRNP snRNPs (small nuclear ribonucleoproteins)] to form the U4/U6 di-snRNP during the assembly of the [http://en.wikipedia.org/wiki/Spliceosome spliceosome] <ref name="Bae">PMID:17320109</ref>. This protein contains four RNA recognition motifs (RRMs) that function in the binding of Prp24 to U6 snRNA <ref name="Bae"/>. These RRM domains are conserved in structure and sequence in proteins orthologous to Prp24 in ''Homo sapiens'' and ''Schizosaccharomyces pombe'', as well as in other proteins containing RRMs <ref name="Rader">PMID:12458792</ref>. | '''Prp24''' ('''Pr'''e-mRNA splicing '''P'''rotein '''24''') is a [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae ''Saccharomyces cerevisiae''] yeast protein that functions in the formation of base pair interactions between the [http://en.wikipedia.org/wiki/U6_spliceosomal_RNA U6] and [http://en.wikipedia.org/wiki/U4_spliceosomal_RNA U4] [http://en.wikipedia.org/wiki/SnRNP snRNPs (small nuclear ribonucleoproteins)] to form the U4/U6 di-snRNP during the assembly of the [http://en.wikipedia.org/wiki/Spliceosome spliceosome] <ref name="Bae">PMID:17320109</ref>. This protein contains four RNA recognition motifs (RRMs) that function in the binding of Prp24 to U6 snRNA <ref name="Bae"/>. These RRM domains are conserved in structure and sequence in proteins orthologous to Prp24 in ''Homo sapiens'' and ''Schizosaccharomyces pombe'', as well as in other proteins containing RRMs <ref name="Rader">PMID:12458792</ref>. | ||
== Introduction == | == Introduction == | ||
[[Image:Spliceosome.jpg |frame|left| Figure 1. Assembly and disassembly of the spliceosome in ''Saccharomyces cerevisiae'' (after Staley and Guthrie 1998 <ref name="Staley"/>)]] | |||
[[Image:Transester.jpg |frame|left| Figure 2. The transesterificiation reactions of pre-mRNA splicing (after Brow 2002<ref name="Brow review"/>) ]] | [[Image:Transester.jpg |frame|left| Figure 2. The transesterificiation reactions of pre-mRNA splicing (after Brow 2002<ref name="Brow review"/>) ]] | ||
=== Pre-mRNA Splicing === | === Pre-mRNA Splicing === | ||
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== Structure == | == Structure == | ||
The key structural elements of Prp24 are the conserved RNA recognition motifs (RRMs). These motifs are found in many proteins with RNA binding properties and contain conserved RNP elements that are recognizable by their primary sequence <ref name="Shannon"/>. For several years, Prp24 was thought to contain three RRMs, termed RRM 1, RRM 2, and RRM 3 <ref name="Shannon"/>. However, analysis of homologs of Prp24 from several different species allowed the identification of a fourth RRM in Prp24 of ''S. cerevisiae'', albeit one that was much less highly conserved and not easily recognizable by its RNP-consensus domain <ref name="Rader"/>. | The key structural elements of Prp24 are the conserved RNA recognition motifs (RRMs). These motifs are found in many proteins with RNA binding properties and contain conserved RNP elements that are recognizable by their primary sequence <ref name="Shannon"/>. For several years, Prp24 was thought to contain three RRMs, termed RRM 1, RRM 2, and RRM 3 <ref name="Shannon"/>. However, analysis of homologs of Prp24 from several different species allowed the identification of a fourth RRM in Prp24 of ''S. cerevisiae'', albeit one that was much less highly conserved and not easily recognizable by its RNP-consensus domain <ref name="Rader"/>. | ||
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Several additional roles for Prp24 have been suggested in spliceosome assembly/disassembly, although nothing has been sufficiently supported. A genetic interaction in which Prp24 mutation suppressed a Prp21 (a component of the U2 snRNP) mutation suggested that the two proteins may interact during the base pairing of U2 and U6 at the 5' splice site; however, further investigation failed to produce evidence of a definite interaction between the two proteins, although the authors maintained that a transient interaction between Prp24 and Prp21 may exist in an intermediate form of the assembling spliceosome <ref name="Vaidya"/>. It has also been suggested that Prp24 may also assist in the formation of U4/U5.U6 <ref name="Ryan">PMID:12212846</ref> or in the destabilization of U6 from U2 upon completion of splicing to release free U6 snRNP,<ref name="Vidaver"/>, but there is insufficient evidence to conclusively support these functions of Prp24. | Several additional roles for Prp24 have been suggested in spliceosome assembly/disassembly, although nothing has been sufficiently supported. A genetic interaction in which Prp24 mutation suppressed a Prp21 (a component of the U2 snRNP) mutation suggested that the two proteins may interact during the base pairing of U2 and U6 at the 5' splice site; however, further investigation failed to produce evidence of a definite interaction between the two proteins, although the authors maintained that a transient interaction between Prp24 and Prp21 may exist in an intermediate form of the assembling spliceosome <ref name="Vaidya"/>. It has also been suggested that Prp24 may also assist in the formation of U4/U5.U6 <ref name="Ryan">PMID:12212846</ref> or in the destabilization of U6 from U2 upon completion of splicing to release free U6 snRNP,<ref name="Vidaver"/>, but there is insufficient evidence to conclusively support these functions of Prp24. | ||
</StructureSection> | |||
__NOTOC__ | |||
==3D structures of pre-mRNA-splicing factors== | ==3D structures of pre-mRNA-splicing factors== | ||