11BIS1012013MicroRNALect11

Lrodriguez 2013

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Unformatted text preview: ed by Immediately Drosha into short hairpin RNAs (shRNA) or pre-miRNAs. Drosha The shRNAs undergo active transport from nucleus to cytoplasm where they The are recognized by Dicer. are Dicer reduces the shRNA into a short-lived double strand siRNA The non-siRNA (passenger strand) is separated from the antisense or guide The strand and degraded, releasing a functional siRNA/RISC complex. strand Drosha Nucleus Cytoplasm RISC Dicer miRNA gene Cropping Transcription pri-miRNA Nuclear export pre-miRNA (shRNA) Dicing miRNA separation ds-siRNA BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez Functional RISC siRNA 13 RNA Induced Silencing Complex (RISC) Dicer/R2D2 binds and Dicer/R2D2 trims the small dsRNA (miRNA). (miRNA). This dsRNA is transferred This to Argonaut (Ago2). to The helicase of Ago2 The unwinds the “passenger” and “guide” strands. The guide strand binds the The target RNA and the endonuclease (Slicer) cuts the target RNA, followed by exonuclease digestion. by http://helicase.pbworks.com/w/page/17605619/Emily-Devol BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 14 Processing of Small Interfering RNA (siRNA)* dsRNA ­ Double stranded RNA is introduced into a cell and gets trimmed by the enzyme “dicer” to form siRNA. siRNA Double then binds to the RNA-Induced Siilencing Complex (RISC) complex and is unwound. The anitsense RNA nduced lencing omplex complexed with RISC binds to its corresponding mRNA which is the cleaved by the RNase “slicer” rendering it inactive. SiRNA can be replicated and become infectious (#6, 7, 5). it BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 15 RNAi Therapy BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 16 Biological function comes from protei...
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This note was uploaded on 02/12/2014 for the course BIS 101 taught by Professor Simonchan during the Spring '08 term at UC Davis.

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