Cronenberger Gwendolyn Quintana 01187235 1 Draw the nucleus and label all its parts 2 Define regarding protein transport through nuclear pores a Ran is a small protein initially located inside of the nucleus which carries a molecule of GTP Ran GTP binds to a nuclear transport receptor and is transported through nuclear pores into the cytosol After hydrolysis of GTP Ran GDP falls off the transport receptor and seeks out a protein destined for the nucleus b GTPase activating protein GAP regulates protein activity by phosphate addition and removal to GTP Activation of GTP requires a tightly bound GTP to a GTP binding protein c Guanine nucleotide exchange factor GEF activate GTPases by stimulating the release of GDP to allow binding of GTP d Nuclear transport factor 2 NTF2 is a protein that interacts with the nuclear pore e f complex glycoprotein and returns Ran GDP back to the nucleoplasm Importin is a protein that moves other protein molecules into the nucleus by binding to a specific recognition sequence or nuclear localization signal Exportin a molecule which bind signaling sequences called nuclear export signals NES to facilitate exit from the nucleus They must bind RanGTP to form a ternary complex with their export cargo 3 Trace the Ran cycle into out of the nucleus Include influences of Ran on importine exportin cargo a Promotion of complex formation Importin is a transport proteins that binds to nuclear localization signal of cargo protein in the cytoplasm Hydrolysis allows for the dissociation of Ran GTP and association of importin to the nuclear transport receptor b Dissociation of complex The nuclear transport receptor becomes dissociated with the importin upon arrival into the nucleus by binds of GTP Ran This complex subsequently travels to the cytosol and become dissociated via hydrolysis and presence of nucleus bound proteins Cronenberger Gwendolyn Quintana 01187235 4 Trace the protein import from the ribosomes into the nucleus Include all factors