BIOCH330 Lecture Notes - Lecture 5: U2Af2, Alternative Splicing, Atp Hydrolysis

• School: University of Alberta
• Department: Biochemistry
• Course: BIOCH330
• Professor: Andrew Macmillan

Document Summary

Atp is required bees it mediates these steps. These atp dependent transitions are dependent on protein factors associated with the spliteosomes called helicases. Unwind or promote annealing(formation) of na structures in an atp dependent fashion. U5 snrnp protein brr2 catalyzes u4/u6 > u2/u6 transition. ^^ interacts with prp8 protein : regulation. Mutations in brr2 and prp8 proteins are the cause of a degenerative condition leading to blindness: retinisis pigmentosa. The atp hydrolysis of helicases acts as a clock. If transitions in the spliceosome don"t match the timing of the clock, the message is targeted for degradation. If the associations are too weak or too strong atp recognizes that there is something wrong. Females: sxl binds to proximal 3" splice site at ppt. U2af binding blocked by sxl protein (sex lethal protein) U2af now binds to distal 3" splice site and u2 snrnp is recruited there. Male: synthesis of truncated / non functional proteins.