What are two examples of protein targeting signals?
- ER: hydrophobic signal sequence
2. Lysosome: M6P
What is the zellweger syndrome?
Where is the defect, what cuases it, what are some consequences
- a protein targeting disease
- Peroxisomal targeting defect, the peroxisomal enzymes accumulate in the cytosol
- neural, cardiovasclar, renal, adrenal dystrophies
- accumulate very long chain fatty acids
- cataracts, glaucoma, retinal detachment
- average lifespan 12 weeks
- no treatment
What does NLSs stand for?
Nuclear Localization Signals
What does NLS do?
direct proteins to the nucleus
What is NPC
nuclear pore complex
What does NPC function as?
Entrance to the nucleus for proteins
It is perhaps the largest protein complex in the cell and has more than 30 dif proteins arranged. 50x greater than ribosomes
What does the secretory pathway do? Give some examples
it prepares and packages proteins for secretion
i.e hormones blood albumin antibodies snot digestive enzymes low density lipoprotein
What does the secretory pathway do for the integral membrane proteins?
It also inserts and folds integral membrane proteins.
- ion channels
- nutrient transporters
- hormone receptors
- neurotransmitter receptors
- cell adhesion molecules
How does botulism and tetanus neurotoxins block neuronal exocytosis and neurotransmission?
botulism and tetanus neurotoxins destroy SNARE proteins
