BIOL 2905 Lecture Notes - Lecture 7: Reverse Genetics, Chromatin, Microrna
13 Oct 2017
School
Department
Course
Professor
Document Summary
Rnai via mirna: enzyme called dicer which breaks dna into many parts. The double stranded mirna starts to form complexes with other proteins. One of the strands of mirna is not used- the other strand is up- taken by risc (rna induced silencing complex). mirna is transcribed from o(cid:374)e ge(cid:374)e (cid:271)ut it targets other ge(cid:374)es. You do(cid:374)"t always get perfe(cid:272)t (cid:373)at(cid:272)h with mirna & target sequence. Risc looks for mrna sequences that are complementary to mirna within complex. No protein expression- regulation is post-transcriptionally which inhibits translation: over 450 distinct mirna, risc includes the microrna, which then can find complementary mrna strands to bind to. Mechanisms is sequence specific but same microrna can shut down several mrnas: dicer cleaves rna to one mirna strand. This represses transcription b/t attracting enzymes that methylate dna: this complex signal for other enzymes that represses & shuts down transcription, rits complexes with dna to prevent transcription.
