Characterisation of the yeast RNA helicase Prp43

INDEXSUMMARY1. INTRODUCTION1.1. RNA helicases1.2. Pre-mRNA splicing1.3. Ribosome biogenesis1.4. G-patch proteins1.5. Aims2. MATERIALS AND METHODS2.1. Materials2.2. Methods3. RESULTS3.1. Identification of Cmg1-interacting helicases3.2. Analysis of the Cmg1 - Prp43 interactionin vitro3.3. Identification of Cmg1 and Prp43interacting domains3.4. Effect of Cmg1 on the RNA binding affinityof Prp433.5. Prp43 ATPase activity in the presence ofCmg13.6. Cmg1 cellular localisation3.7. Submitochondrial localisation of Cmg13.8. Analysis of mitochondrial metabolism uponcmg1 deletion or overexpression3.9. Cell growth and survival in cmg1 deletion and overexpression strains3.10. Relocalisation of Cmg1 and Prp43 underapoptotic conditions3.11. Mitochondrial binding partners of Prp43 inapoptosis3.12. Prp43 localisation in the complex IIIdeficient strain3.13. Localisation of Prp43 upon G-patch proteinoverexpression3.14. G-patch proteins compete for Prp43binding3.15. Overexpression of G-patch proteins affectsprecursor ribosomal RNA processing4. DISCUSSION4.1. Characterisation of the orphan G-patchprotein Cmg14.2. Prp43 at mitochondria in apoptosis4.3. Recruitment of helicases to their target sites4.4. Regulation of RNA helicases by cofactorcompetition4.5. Conclusions5. REFERENCESPUBLICATIONACKNOWLEDGMENTSCURRICULUM VITAESoftcover, 17x24RNA helicases have many important roles in cell metabolism and are involved in numerous pathways, e.g. translation, pre-mRNA splicing and biogenesis. Interestingly, an increasing number of RNA helicases have been shown to be required for more than one cellular pathway. Therefore, protein cofactors have been suggested to recruit multifunctional RNA helicases to their substrates and regulate their activity. The best characterised family of helicase cofactors are G-patch proteins, which all contain a glycine-riche domain. This work focuses on the characterisation of the yeast RNA helicase Prp43 and its G-patch protein cofactors. Additionally, a new G-patch protein cofactor of Prp43 was identified and characterised. Together, the data suggest that protein cofactors can regulate the distribution and activity of RNA helicases in different pathways