Eukaryotic Gene Expression
por Clara Bachere
1. 3) Translational --> translation
1.1. miRNA dna siRNA
1.1.1. miRNA - bind to complementary sequences to degrade target mRNA / prevent translation - formed from hairpin precursor molecule
1.1.2. siRNA - formed from longer double-stranded RNA - heterochromatin formation and can block large regions of chromosomes
2. 4) Post-Translational --> protein
2.1. Protein Degradation - ubquitin is added to protein to be degraded, this signals a proteasome to come, protein is degraded and fragments are left behind and the proteasome and ubiquitin are recycled
3. 1) Transcriptional --> transcription
3.1. Control Elements --> promote/prevent transcription
3.1.1. Histone Acetylation --> add acetyl, loosens chromatin structure, promotes trans
3.1.2. DNA Methylation --> methyl condenses chromatin, restricts trans
3.1.2.1. X inactivation - Embryonic cell differentiation - Genomic imprinting
3.1.3. Phosphorylation --> phosphate + methyl = promotes trans
4. 2) Post-Transcriptional --> mRNA
4.1. Alternative RNA Processing
4.1.1. Regulatory proteins control combination of eons and introns
4.2. mRNA Degradation
4.2.1. poly a tail shortening
4.3. Initiation of Translation
4.3.1. regulatory proteins bind to UTR5' to block translation from happening