more regulating gene expression

Fig 16.1 Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational Fig 15.1

Fig 16.1 Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational Fig 15.1

Fig Alternate Splicing in Drosophila Sex Determination

Alternate splicing leads to sex determination in fruit flies Fig 23.25

Molecular Biology of the Cell 4th ed. Alberts et al. Fig mRNA transport is an important regulatory step

Molecular Biology of the Cell 4th ed. Alberts et al. Fig mRNA can be localized to a specific parts of a cell (from Drosophila embryo)

Molecular Biology of the Cell 4th ed. Alberts et al. Fig 7.98 At least 3 mechanisms are involved: Directed transport via cytoskeleton Random diffusion and trapping Degradation and local protection

A processed mRNA ready for translation Protects from degradation/ recognition for ribosome Protects from degradation/ transport to cytoplasm 5’ untranslated region 3’ untranslated region

Molecular Biology of the Cell 4th ed. Alberts et al. Fig mRNA with 3’ UTR properly localized mRNA without 3’ UTR improperly localized

Fig 16.1 Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational Fig 15.1

Fig 16.1 Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational Fig 15.1

Fig Regulation of iron assimilation in mammals: Regulating of Translation

Fig Ferritin is regulated at translation

C. elegans is commonly used to study development

C. elegans development

C. elegans mutants with cells that do not develop properly.

The product of these genes was found to be RNA?

Cell vol. 116, MicroRNAs (miRNA) are ~22nt RNAs that play important regulatory roles

How do microRNAs control gene expression? miRNA expressed miRNA processed to ~22nt RNA Mature miRNA Fig and

A processed mRNA ready for translation: microRNAs inhibit translation by binding to the 3’ end of mRNA microRNA bind to 3’-UTR 5’-UTR 3’-UTR

miRNA expressed miRNA processed to ~22nt RNA Mature miRNA the 3’ end with attached microRNA interacts with the 5’ end, blocking translation Fig and

miRNAs can lead to methylation of DNA that leads to inhibition of transcription

microRNAs primarily target gene products that function during development Tbl 1

PNAS vol. 101 #1 pg , 2004 tissue specific expression of mouse microRNA

Fig 16.1 Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational

Phosphorylation and dephosphorylation of proteins can change activity

Ubiquitinization targets proteins for degradation

Some proteins function in the cytoplasm; others need to be transported to various organelles.

How can proteins be delivered to their appropriate destinations?

Fig Proteins are directed to their destinations via signals in the amino acid sequence

Protein Destinations: secretion or membrane

Signal sequences target proteins for secretion

Translation of secreted proteins

Translation of membrane bound proteins

Translation of secreted or membrane bound proteins This step determines secretion or membrane bound.

Protein Destinations: nucleus Signal anywhere in protein, Translation in cytoplasm, Signal not removed

Protein Destinations: mitochondria or chloroplast Signal translated first, Translation in cytoplasm, Signal removed

Protein Destinations: signals in protein determine destination Tbl 13.8

Next: Development- differentiating cells to become an organism