User:Wally Novak/Sandbox Whitaker: Difference between revisions
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==Function== | ==Function== | ||
===General Overview=== | ===General Overview=== | ||
The U5 snRNP consists of several proteins which are highly conserved from yeast to humans. These proteins consist of Prp8, Snu114, Brr2, Prp28, Snu40/52K, and <scene name='79/798410/Dib1/1'>Dib1</scene><ref>PMID:11720284</ref>, however, only Prp8, Snu114, and Brr2 remain in complex with the U5 snRNA while the spliceosome is activated <ref name="Irish">PMID:23354046</ref>. These proteins are necessary for the remodeling of the spliceosome and may play a role in maintaining catalytic activity at the active center of the spliceosome <ref name="Irish" />. Assembly of the U5 snRNP is followed by the formation of the U4/U6.U5 tri-snRNP which is the last remaining complex necessary to form the complete spliceosome and is therefore vital for its function. | The U5 snRNP consists of several proteins which are highly conserved from yeast to humans. These proteins consist of <scene name='79/798410/Yeast_prp8/1'>Prp8</scene>, Snu114, <scene name='79/798410/Yeast_brr2/1'>Brr2</scene>, Prp28, Snu40/52K, and <scene name='79/798410/Dib1/1'>Dib1</scene><ref>PMID:11720284</ref>, however, only Prp8, Snu114, and Brr2 remain in complex with the U5 snRNA while the spliceosome is activated <ref name="Irish">PMID:23354046</ref>. These proteins are necessary for the remodeling of the spliceosome and may play a role in maintaining catalytic activity at the active center of the spliceosome <ref name="Irish" />. Assembly of the U5 snRNP is followed by the formation of the U4/U6.U5 <scene name='79/798410/Prp8_snu114_brr2_5gan/1'>tri-snRNP</scene> which is the last remaining complex necessary to form the complete spliceosome and is therefore vital for its function. | ||
===U5 snRNA=== | ===U5 snRNA=== | ||
The U5 snRNA interacts directly with the 5’ exon before the first step of splicing and with the 5’ and 3’ exons following the first step of splicing <ref name="Keefe">PMID:9430647</ref>. These U5–exon interactions are essential for tethering and aligning the exons for ligation during the second step of splicing <ref name="Keefe" />. | The U5 snRNA interacts directly with the 5’ exon before the first step of splicing and with the 5’ and 3’ exons following the first step of splicing <ref name="Keefe">PMID:9430647</ref>. These U5–exon interactions are essential for tethering and aligning the exons for ligation during the second step of splicing <ref name="Keefe" />. | ||
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==Protein Interactions== | ==Protein Interactions== | ||
The U5 snRNP is one of the five subunits which come together to form the spliceosome and is, therefore, a key protein for eukaryotic mRNA processing. U5 snRNP is a complex which consists of U5 snRNA, Brr2, Snu114, and Prp8. Prp8 also interacts with other proteins of the spliceosome, the snRNAs and extensively with the pre-mRNA <ref name="Irish" />. It has been shown that Prp8 crosslinks directly to the pre-mRNA 5’ splice site, the branch site, and the 3’ splice site as well as U5 and U6 snRNAs localizing it to the heart of the spliceosome <ref name="Irish" />. In yeast, Prp8 makes extensive direct contacts with the U5 snRNA including the highly conserved U5 loop 1 and IL1 <ref name="Irish" />. | The U5 snRNP is one of the five subunits which come together to form the spliceosome and is, therefore, a key protein for eukaryotic mRNA processing. U5 snRNP is a complex which consists of U5 snRNA, Brr2, Snu114, and Prp8. Prp8 also interacts with other proteins of the spliceosome, the snRNAs and extensively with the pre-mRNA <ref name="Irish" />. It has been shown that Prp8 crosslinks directly to the pre-mRNA 5’ splice site, the branch site, and the 3’ splice site as well as U5 and U6 snRNAs localizing it to the heart of the spliceosome <ref name="Irish" />. In yeast, Prp8 makes extensive direct contacts with the U5 snRNA including the highly conserved U5 loop 1 and IL1 <ref name="Irish" />. | ||
Following successful assembly of the U5 snRNP, a tri-snRNP consisting of U4, U5 and U6 is formed which is then incorporated into the active spliceosome. <Structure load='5gan' size='400' frame='true' align='right' caption='U4/U6.U5 tri-snRNP'/> | Following successful assembly of the U5 snRNP, a <scene name='79/798410/Prp8_snu114_brr2_5gan/1'>tri-snRNP</scene> consisting of U4, U5 and U6 is formed which is then incorporated into the active spliceosome. <Structure load='5gan' size='400' frame='true' align='right' caption='U4/U6.U5 tri-snRNP'/> | ||
