alternate sigma factor usage : controls selective transcription
DESCRIPTION
s 70. Ways to Regulate Transcription. Alternate sigma factor usage : controls selective transcription of entire sets of genes. vegetative (principal s). +1. צמיחה. (16-19 bp). (5-9 bp). A. TTGACA. TATAAT. heat shock. +1. s 32. (13-15 bp). - PowerPoint PPT PresentationTRANSCRIPT
Alternate sigma factor usage: controls selective transcription of entire sets of genes
s32
s60
vegetative(principal s)
heat shock
nitrogen starvation
s70
TTGACA TATAAT(16-19 bp) (5-9 bp) A
+1
CNCTTGA CCCATNT(13-15 bp) (5-9 bp) A
+1
CTGGNA TTGCA(6 bp) (5-9 bp) A
+1
Ways to Regulate Transcription
צמיחה
!19.6.2008התרגיל ביום חמישי זה –
באוקריוטיםטרנסקריפציה
Pre-mRNA
* microRNAs (miRNA) RNA molecules of about 21–23 nucleotides in length, which regulate gene expression. are processed from primary transcripts known as pri-miRNA.
5’UTR
3’UTR
בעכבר כבד בתאי
RNA polymerase
ותדירות יעילות 1מיקום +) בזלית ) נמוכה רמה
ESRE
אינטרונים
אין אחידות במיקום וברצפי הבקרה בין
גנים שונים.
הטרנסקריפציה שלבי
•Initiation
•Elongation
•Termination
- איניציציה פרה קומפלקס
ותדירות יציבותזה קומפלקס יצירתוקצב כמות את קובעת
- ה RNAסינטזת
אוקריוטים בתאים טרנסקריפציה של אקטיבציה אופן
Stages in Initiation of Transcription
• Bacterial transcription• Closed complex:
holoenzyme+promoter• Open complex (DNA
melting, not need ATP)• Abortive transcripton• Productive initiation
– Transcribe past +9
– Sigma dissociates
• Elongation
• Eukaryotic transcription
• Preinitiation complex (PIC) assembly
• PIC activation (DNA melting, needs ATP)
• Abortive transcription• Productive initiation
– CTD phosphorylated
– Promoter clearance
• Elongation
initiation
Elongation
NTPs
TERMINATION
• RNA polymerase meets the terminator• Terminator sequence: AAUAAA
• RNA polymerase releases from DNA• Prokaryotes-releases at termination
signal• Eukaryotes-releases 10-35 base pairs
after termination signal
קומפלקס האלונגציה
transcription
Transcription regulation
Gene expression
Basics of cell biology:development
Fertilized egg
Basics of cell biology:development
Cells differentiationis due to different geneSwitches going on and off
These cells are differentbecause they express a subset of their 24,000 genes
GenePromoter
To specify a new cell: place it in the right environment
or
GenePromoter
To specify a new cell: place it in the right environment
orSubstitute drugs/proteins for environmentMophogens
FGF
Hedgehog
EGF
Wnt
Retinoic acid
HGF
Chromosome localization in interphase
In interphase, chromosomes appearto be localized to a sub-region of thenucleus.