Brr2p carboxy-terminal Sec63 domain modulates Prp16 splicing RNA helicase.

Olivier Cordin (1, 2) , Daniela Hahn (2) , Ross Alexander (2) , Amit Gautam (2) , Cosmin Saveanu (3) , J David Barrass (2) , Jean D Beggs (2)

1 EGM (UMR_8261 / FRE_3630) - Expression Génétique Microbienne
2 Wellcome Trust Centre for Cell Biology
3 Génétique des Interactions macromoléculaires / Genetics of Macromolecular Interactions

RNA helicases are essential for virtually all cellular processes, however, their regulation is poorly understood. The activities of eight RNA helicases are required for pre-mRNA splicing. Amongst these, Brr2p is unusual in having two helicase modules, of which only the amino-terminal helicase domain appears to be catalytically active. Using genetic and biochemical approaches, we investigated interaction of the carboxy-terminal helicase module, in particular the carboxy-terminal Sec63-2 domain, with the splicing RNA helicase Prp16p. Combining mutations in BRR2 and PRP16 suppresses or enhances physical interaction and growth defects in an allele-specific manner, signifying functional interactions. Notably, we show that Brr2p Sec63-2 domain can modulate the ATPase activity of Prp16p in vitro by interfering with its ability to bind RNA. We therefore propose that the carboxy-terminal helicase module of Brr2p acquired a regulatory function that allows Brr2p to modulate the ATPase activity of Prp16p in the spliceosome by controlling access to its RNA substrate/cofactor.

Domaines: Biologie moléculaire

Olivier Cordin, Daniela Hahn, Ross Alexander, Amit Gautam, Cosmin Saveanu, et al.. Brr2p carboxy-terminal Sec63 domain modulates Prp16 splicing RNA helicase.. Nucleic Acids Research, 2014, 42 (22), pp.13897-910. ⟨10.1093/nar/gku1238⟩. ⟨pasteur-01427502⟩