Clathrin coated vesicle

this presentation contain the basic introduction of CCVs.
who discover this?
what are the structure of CCVs?
role of CCVs
advantage and their fuctions.

1. CLATHRIN COATED VESICLES Mansi Prajapati

2. CLATHRIN COATED VESICLES Clathrin coated vesicles are agent of the specific internalization of certain cell surface receptors in most eukaryotic cells. whose function is related to the endocytosis and the intracellular transport of membranes and soluble proteins.

3. Clathrin was first isolated and named by BARBARA PEARSE in 1975. Coated vesicles can be isolated and purified from brain and other tissues by negative staining technique. DISCOVERY OF CCVs A lattice of pentagons and hexagons, which constitute the coat, the coat is mainly composed of major protein of 180,000 Daltons named CLATHRIN.

4. STRUCTURE It forms a triskelion shape composed of three light chain and three heavy chains. When the triskelion interact they forms a polyhedral lattice that surround the vesicle . The three heavy chain provide the structural backbone of the clathrin lattice. The three light chains are regulate the assembly and disassembly.

5. ROLE OF CLATHRIN COATED VESICLES CLATHRIN MEDIATED ENDOCYTOSIS Firstly the receptors binds to the cargo molecules. Adaptin proteins bind its one end with receptor and another end with clathrin . Recruitment of clathrin molecules cause the membrane to bend and invaginate .

6. Now, the vesicles uncoated, losing clathrin lattice. The vesicles fuses with the endosome . the low endosomal pH causes the receptors to release their cargo molecules. Empty receptors are recycled to plasma membrane in vesicles that bud off from the endosome .

7. The endosomal content is then delivered to a lysosome which contains hydrolytic enzymes capable of degradation. Dynamin forms a ring around the stalk. GTP hydrolysis causes a conformational changes in the dynamin ring, leading to fission of the coated vesicles from the plasma membrane. The photograph showing that clathrin mediated endocytosis

8. VIDEO This video showing the clathrin mediated endocytosis and degradation

9. ADVANTAGE OF CCV’s CLATHRIN Clathrin -coated vesicle carry cargo onward from mature cisternae and also any cargo back from the plasma membrane to endosomes and other organelles such as TGN and lysosomes . Hence responsible for transport in both direction. COPI COPI coated vesicle act as retrieval vesicles that bring back protein, which enter the default pathway. for example, the ER resident proteins enter back from the ERGIC and cis Golgi cisternae into the ER lumen, similarly the Golgi resident proteins are retrieved back from TGN to earlier cisternae . COPII COPII coated vesicle carry out the transport from the ER lumen to successive cisternae of the GOLGI complex.

10. FUNCTIONS OF CCV’s It act as a Multifunctional proteins. Uptake of extra cellular yolk into chicken oocytes. Transfer of maternal immunoglobulin ( IgG ) through the placenta into the fetus. Incorporation into cells of macromolecules and protein bound nutrients. The recycling of membranes from exocytose secretary granules and synaptic vesicles.

11. Thank you