Coated Vesicles in Cellular Transport Processes Flashcards
what is an example of a coat on a vesicle?
Clathrin
Why are there different types of protein coats on vesicles?
Because the specific type of protein coat helps in the sorting of molecules that are fated for different destinations in the cell
What are clathrin coated vesicles involved in, in terms of origin and destination of the vesicle?
Clathrin coated vesicles are involved in the selective transport of proteins from the TGN to endosomes and in the endocytosis of receptor-ligand complexes from the plasma membrane
what are clathrin coated vesicles surrounded by?
two multimeric proteins - clathrin and adaptor protein
Why is using clathrin coated vesicles advantageous to the cell?
Because the unique shape of the clathrin proteins and the way they assemble to form clathrin coats provides the driving force that causes flat membranes to curve and form spherical vesicles
How is clathrin structured… what does it look like?
One clathrin triskelion is located at each vertex of the polygonal lattice
Each polypeptide leg extends along two edgesof the lattice, with the knee of the clathrin heavy chain located at an adjacent vertex
How do adaptor protein complexes come into play with clathrin coated vesicles?
AP complexes mediate the attachment of clathrin to proteins embedded in the plasma membrane
Also sites for the regulation of clathrin assembly and disassembly
What are the factors that affect the ability of AP complexes to bind to clathrin?
pH, phosphorylation and dephosphorylation
What shape to clathrin proteins initially make?
What shape after more are incorportated?
Hexagon
Hexagon and Pentagon
What is the protein that is triggered by an accumulation of clathrin?
Dynamin- participates in the process
required for budding of the vesicle and coated pit construction
