Quiz 2 Material Endomembrane System ER Protein Import ER Protein Folding Intracellular Vesicle Transport Golgi Endocytosis Lysosomes Exocytosis Exocytosis used in cleavage furrow phagocytosis wound repair DATA Exosomes Exosomes secreted cid 3 vesicles CBIO3400 secreted vesicles a way for cells to communicate microERNA controls transcripBon translaBon elements originate from late endosomes called mul2Qvesicular bodies contain intraluminal vesicles anti cid 882 transferrin cid 882 receptor cid 3 antibody cid 3 Isolated cid 3 exosomes Exosomes are cid 3 membrane cid 3 vesicles cid 3 50 cid 882 100 cid 3 nm cid 3 in cid 3 diameter cid 3 secreted cid 3 by cid 3 a cid 3 wide cid 3 range cid 3 of cid 3 animal cid 3 cell cid 3 types cid 3 They cid 3 originate cid 3 from cid 3 late cid 3 endosomes cid 3 called cid 3 MultiVesicular Bodies cid 3 MVB cid 3 that cid 3 contain cid 3 intraluminal cid 3 vesicles cid 3 Exocytosis slide 1 of 3 DATA CBIO3400 from TGN cell exterior Secretion cid 3 of cid 3 soluble cid 3 glycoproteins Lipids cid 3 and cid 3 transmembrane proteins cid 3 for cid 3 the cid 3 PM cid 882 cid 882 cid 882 Constitutive cid 3 and cid 3 regulated cid 3 pathway Exocytosis from cid 3 trans cid 3 Golgi cid 3 network cid 3 TGN cid 3 to cid 3 the cid 3 cell cid 3 exterior many hormones neuropepBdes etc are secreted via regulated pathway want to secrete in controlled process not just randomly DATA Excytosis cid 3 from cid 3 trans cid 3 Golgi cid 3 to cid 3 the cid 3 cell cid 3 exterior CBIO3400 Exocytosis slide 2 of 3 cid 882 Many cid 3 hormones cid 3 neuropeptides cid 3 etc cid 3 are cid 3 secreted cid 3 by cid 3 the cid 3 regulated cid 3 pathway cid 882 Vesicle cid 3 contents cid 3 get cid 3 more cid 3 and cid 3 more cid 3 concentrated cid 3 as cid 3 they cid 3 mature cid 882 Cleavage cid 3 of cid 3 pro cid 882 peptides cid 3 and cid 3 polyproteins from TGN cell exterior vesicle contents get more more concentrated as they mature Exocytosis slide 3 of 3 from TGN cell exterior cleavage of proEpepBdes polyproteins preQprotein needs a signal sequence Why preEprotein pepBdes that are too short can t go into ER can t be recognized let in by ER translocon proQprotein needs to be processed preQproQprotein needs a signal sequence to be processed THM original sequence cleaved in several steps down to nal products DATA CBIO3400 Excytosis cid 3 from cid 3 trans cid 3 Golgi cid 3 to cid 3 the cid 3 cell cid 3 exterior cid 882 Many cid 3 hormones cid 3 neuropeptides cid 3 etc cid 3 are cid 3 secrted by cid 3 the cid 3 regulated cid 3 pathway cid 882 Vesicle cid 3 contents cid 3 get cid 3 more cid 3 and cid 3 more cid 3 concentrated cid 3 as cid 3 they cid 3 mature cid 882 Cleavage cid 3 of cid 3 pro cid 882 peptides cid 3 and cid 3 polyproteins What cid 3 is cid 3 a cid 3 pre cid 882 pro cid 882 protein cid 3 Ac cid 882 Ser cid 882 Tyr cid 882 Ser cid 882 Met cid 882 Glu cid 882 His cid 882 Phe cid 882 Arg cid 882 Trp cid 882 Gly cid 882 Lys cid 882 Pro cid 882 Val Tyr cid 882 Gly cid 882 Gly cid 882 Phe cid 882 Met cid 882 Thr cid 882 Ser cid 882 Glu cid 882 Lys cid 882 Ser cid 882 Gln cid 882 Thr cid 882 Pro cid 882 Leu cid 882 Val cid 882 Thr cid 882 Leu cid 882 Phe cid 882 Lys cid 882 Asn cid 882 Ala cid 882 Ile cid 882 Ile cid 882 Lys cid 882 Asn cid 882 Ala cid 882 Tyr cid 882 Lys cid 882 Lys cid 882 Gly cid 882 Glu Regulated Exocytosis controlled fast primed Regulated cid 3 exocytosis Synaptic cid 3 vesicles DATA CBIO3400 cid 882 small cid 3 dia cid 3 50 cid 3 nm cid 882 are cid 3 recycled cid 3 and cid 3 refilled cid 882 can cid 3 fire cid 3 1000x sec vesicles EX rat mast cells before arer local acBvaBon THM can localize acBvaBon of exocytosis pathway in cells synap2c vesicles specialized secretory vesicles small recycled reE lled re very quickly Synap2c Vesicles only allowed to have 1 or 2 VEATPase which generates proton gradient required to shuJle neurotransmiJer from cytoplasm to plasma membrane recycling of synapBc vesicles Explain the e ects of Botox botulism toxin the Shibire mutaBon both block dynamin vesicles can t pinch o can t recycle vesicles anymore no more vesicles paralysis FullQCollapseQFusion KissQ QRun Models of Vesicle Fusion KissQ QRun Model of Vesicle Fusion refers to very short contact Bme w PM not complete fusion w PM allows acBons to be done quickly to be repeated FullQCollapseQFusion Model of Vesicle Fusion SNAREs keep vesicles very close to plasma membrane slightest trigger causes fusion w PM release of contents CBIO3400 Tetanus Toxin DATA a bacterial protease tetanospasmin cleaves synaptobrevin a SNARE motor neurons release neurotransmiJer ACh to sBmulate skeletal muscle contracBon acts on binds inhibitory interneurons blocking their release of ACh inhibitors it s these inhibitors from inhibitory interneurons that eventually allow contracted muscles to relax this is therefore indirect rather than direct acBon X Tetanus cid 3 exotoxin cid 3 is cid 3 a cid 3 neurotoxin cid 3 that cid 3 binds cid 3 to cid 3 inhibitory cid 3 interneurons cid 3 of cid 3 the cid 3 spinal cid 3 cord cid 3 and cid 3 blocks cid 3 their cid 3 release cid 3 of cid 3 inhibitors cid 3 It cid 3 is cid 3 these cid 3 inhibitors cid 3 from cid 3 the cid 3 inhibitory cid 3 interneurons cid 3 that cid 3 eventually cid 3 allow cid 3 contracted cid 3 muscles cid 3 to cid 3 relax cid 3 by cid 3 stopping cid 3 excitatory cid 3 neurons cid 3 from cid 3 releasing cid 3 the cid 3 acetylcholine cid 3 that cid 3 is cid 3 responsible cid 3 for cid 3 muscle cid 3 contraction cid 3 The cid 3 toxin cid 3 by cid 3 blocking cid 3 the cid 3 release cid 3 of cid 3 inhibitors cid 3 keeps cid 3 the cid 3 involved cid 3 muscles cid 3 in cid 3 a cid 3 state cid 3 of cid 3 contraction cid 3 and cid 3 leads cid 3 to cid 3 spastic cid 3 paralysis cid 3 a cid 3 condition cid 3 where cid 3 opposing cid 3 flexor cid 3 and cid 3 extensor cid 3 muscles cid 3 simultaneously cid 3 contract De ne the terms exosome early endosome early endosome where vesicles rst fuse in journey to lysosome early endosome late …