Protein

Protein Synthesis, Processing and Regulation pt.1

Agenda for today

Quiz reviewing translational regulation

​Warm Up

​Cool Down

​Work Out

Jigsaw

Matching Activity

Open Ended

How do proteins achieve their final shape?

Open Ended

Can that shape be altered or regulated?

Open Ended

Are there faulty shapes? If so, how are they prevented?

Protein Folding

Chaperones, Chaperonins and PDI

Chaperones

Chaperones

• Prevents protein aggregation

• Many chaperones are HSPs (heat shock proteins) which means they become up-regulated upon heat shock

• Interact with proteins while they are being synthesized (keeps them linearized)

• They allow proteins destined for the mitochondria to be open to be able to go through aqueous channels

Chaperonins

Open Ended

What do you remember about chaperonins?

Chaperonins

• Chaperonins ALSO prevent protein aggregation

• "Dressing room" where proteins that don't fold properly in the presence of other proteins to fold in isolation

• Transfer from chaperones to chaperonins requires energy

PDI

Open Ended

What do you remember about PDI?

• Disulfide bonds are important determinants in the final shape of proteins

• Cysteines residues form disulfide bonds

• For disulfide bonds to form, there must be an oxidative environment

• PDI fascilitates the formation/rupture of disulfide bonds

• PDI is exclusive to the the ER

​PDI

1. What is reducing and what is oxidizing?

2. ​​The luminal environment contained within membrane bound organelles of the cell (peri nuclear, lumen of the Golgi and ER) is the equivalent to...

3. Where are disulfide bonds preferentially formed?

Questions

Categorize

Options (12)

Collagen I

Deformities in bone and cartilage

Poly-glutamine-containing protein (slippery polymerase repeat it more than 39 times )

Huntingtin

Loss of coordination and balance

Dramatic increase in neuronal cell death

Amyloid Precursor Protein

Reduction of brain cortex leading to loss of memory

Prions: force proteins to adopt the wrong conformation

Neuronal cell death. Cause mainly by eating meat

Plaques (aggregates)

Variant Creutzfeldt-Jakob disease

Organize these options into the right categories

Osteogenesis Imperfecta

Huntington's Disease

Alzheimer's

Transmisible Spongiform Encephalopathy