The U4/U6·U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP) is an essential pre-mRNA splicing factor, which is assembled in a stepwise manner before each round of splicing. It was previously shown that the tri-snRNP is formed in Cajal bodies (CBs), but little is known about the dynamics of this process. Here we created a mathematical model of tri-snRNP assembly in CBs and used it to fit kinetics of individual snRNPs monitored by fluorescence recovery after photobleaching. A global fitting of all kinetic data determined key reaction constants of tri-snRNP assembly. Our model predicts that the rates of di-snRNP and tri-snRNP assemblies are similar and that ∼230 tri-snRNPs are assembled in one CB per minute. Our analysis further indicates that tri-snRNP assembly is approximately 10-fold faster in CBs than in the surrounding nucleoplasm, which is fully consistent with the importance of CBs for snRNP formation in rapidly developing biological systems. Finally, the model predicted binding between SART3 and a CB component. We tested this prediction by Förster resonance energy transfer and revealed an interaction between SART3 and coilin in CBs.

• MeSH
• antigeny nádorové genetika   metabolismus   MeSH
• buněčné jádro genetika   metabolismus   MeSH
• Cajalova tělíska genetika   metabolismus   MeSH
• HeLa buňky MeSH
• jaderné proteiny metabolismus   MeSH
• kinetika MeSH
• lidé MeSH
• malý jaderný ribonukleoprotein U4-U6 genetika   metabolismus   MeSH
• malý jaderný ribonukleoprotein U5 genetika   metabolismus   MeSH
• molekulární modely * MeSH
• nádorové buněčné linie MeSH
• prekurzory RNA genetika   metabolismus   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• ribonukleoproteiny malé jaderné genetika   metabolismus   MeSH
• RNA-helikasy genetika   metabolismus   MeSH
• sestřih RNA genetika   MeSH
• spliceozomy genetika   metabolismus   MeSH
• vazba proteinů genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny nádorové MeSH
• DHX15 protein, human MeSH Prohlížeč
• jaderné proteiny MeSH
• malý jaderný ribonukleoprotein U4-U6 MeSH
• malý jaderný ribonukleoprotein U5 MeSH
• p80-coilin MeSH Prohlížeč
• prekurzory RNA MeSH
• proteiny vázající RNA MeSH
• ribonukleoproteiny malé jaderné MeSH
• RNA-helikasy MeSH
• SART3 protein, human MeSH Prohlížeč
• SNRNP200 protein, human MeSH Prohlížeč