Lysosomes, Protein Turnover, and Peroxisomes

what is inside the lysosome

• acid hydrolases that degrade materials

• ph of 5

• integral membrane lamp prteins that keep interior acidic

acid hydrolase generation

• precursor in golgi is phosphorylated

• mathces up to manose 6 P receptor in membrane

• vesicle with clathrin coat pinches off

• chaperones remove clathrin

• grows into endolysosome

• phospjate taken off

professional phagocytes

cells in the immune system specifically designed to perform phagocytosis

endocytosis

can be pinocytosis of the fluid or receptor medated

receptor mediated endocytosis

• ligand binds to receptor

• coated vesicle forms

• coating comess off

• separation of particles and ligand

• becomes endolysosome and eventually lysosome

clathrin

coats the vesicle like a basket

adaptins

have specificity for the proteins

dynamin

pinches vesicle off the membrane

ubiquination

covalently tags proteins for degradation

exosome biogenesis

• vesicle from autophagy shot out of the lysosome

• released from the PM into the ECF

• may have capability to spread disease to other cell

macroautophagy

• induced by starving cells

• regulated by specific genes

• involved in neuropathologies

parkinson’s

accumulation of bad mitochondria

chaperone mediated autophagy

channels composed from lamp proteins help to take in proteins to be degraded

Tay Sachs disease

• common in ashkenazi jews

• lysosomal storage disease where lipids cannot be degenerated

proteasome

unwinds proteins and chews them up

peroxisomes

produce lipids and degrade alcohols

catalase

markers in peroxisomes, breaks down hydrogen peroxide to H2O

what direct proteins to the peroxisome

have tripeptide signal in C terminus to direct to peroxisome