Wk 7 Pt 2 Flashcards
Constitutive secretion
Materials are transported from secretory vesicle from their site of synthesis and transported and discharged into the extracellular space in a continual manner
Regulation secretion
Materials are stored as membrane bound packages and accumulated on the inside of membrane and discharged only in response to an appropriate stimulus
Endocytosis
Engulfing material from outside surface of cell to compartments such as endosomes or lysosomes located within cytoplasm
COPII- coated vesicles
Move materials from ER “”forward”” to ER Golgi intermediate compartment and vesicular tubular cluster
COPI- coated vesicles
Move materials from ERGIC, VTC and Golgi back to ER, or from trans Golgi to the Cis Golgi
Claritin coated vesicles
A) move materials from TGN to endosomes, lysosomes and plant vacuoles B) move materials from plasma membrane to cytoplasmic compartments (endocytic pathway)
What is the initial trigger for COPII vesicle formation?
SAR1
What does SAR1 regulate?
Assembly and dissamebly of COPII coated vesicles
What proteins does SAR1 recruit?
Sec 23 and Sec 24 (secretory pathway)
What proteins force the vesicles to bud off?
Sec 13 and Sec 31
Pulse chase experiment
Pancreatic cells - producing and secreting digestive enzymes
Add a large dose of radioactive leucine with a pulse phase
Track the position of radioactive proteins by fixing a sample of cells at different times during experiment
Add photographic emulsion after which the samples are developed
The radioactive proteins produce black spots in emulsion grey background revealing the location of proteins within cell
What does pulse chase experiment show?
Secreted proteins move from site of manufacture in RER to Golgi Apparatus
Then to the secretory vesicles and finally to the cells exterior
