31Nuclear pore transport (large aqueous pore) is Colloidal gold spheres coatedwith peptides containing NLSNuclear pore transport(large aqueous pore) isfundmental different fromorganelle transport(lipid bilayer).
32Nuclear import receptors bind nuclear localization signals and nucleoporins
33FG-repeat (Phe-Gly) serve as binding sites for the import receptors. Nuclear import do not alwaysbind to nuclear proteins directly.SolublecytosolicproteinFG-repeat (Phe-Gly) serve as binding sites for the import receptors.
34Nuclear export works like nuclear import, but in reverse Nuclear export signals & nuclear export receptor& nuclear transport receptor (karypherins)tRNA or 5S RNA: nuclei cytosolNLS-particle: cytosol nuclei
35The Ran GTPase drives directional transport through nuclear pore complexes
48Newly mito & chloropl are produced by the growth of preexisting organelle.Their growth depends mainly on the cytosolic protein import
49Translocation into the mitochondrial matrix depends on a signal sequence and protein translocators
50Red = +Yellow = nonpolarOn different sideAmphipathic a helix
51translocase Transport to matrix Insert to inner memb. For protein syn Require for import allnucleus-encodedmitochondria proteinTransport to matrixInsert to inner memb.For protein synIn mito
52Interacting protein: eg Charperone protein hsp70 family All Interacting protein help to prevent aggregation beforeengaging with TOM complex in outer mito membrane.Mitchondrial precursor proteins are imported as unfolded polypeptide chains
53Mitochondrial precursor proteins are imported into the matrix at contact sites that join the inner and outer membranes
73A short signal sequence directs the import of proteins into peroxisomes
74Most peroxisomal membrane proteins are made in the cytosol Peroxins:-at least 23 distinct proteins for driving ATP hydrolysis-deficent result in Zellweger syndrome.Most peroxisomal membrane proteinsare made in the cytosol insert into preexisting peroxisomes.
81ER capture 2 type of protein: Cotranslatioal transport?Posttranslational transport?ER capture 2 type of protein:transmembrane protein & water-sol protein
82In mammalian cells Compared to page 697 p690 Protein import to ER Cotranslational process(chaperone are not required to keep protein unfolded)Protein import to mitochondria, chloroplasts, nuclei, peroxisomes Postranslational process(chaperone needed for unfolding)
109Translocated polypeptide chains fold and assemble in the lumen of the rough ER Important ER resident proteins:PDI (protein disulfide isomerase; produce -s-s-)BiP chaperone protein (prevent aggregate & help to keep in ER)
110Most (Soluble & membrane-bounded) proteins synthesized in the RER are glycosylated by the addition of a common N-linked oligosaccharideVery few protein in cytosol is glycosylated.
111O-linked oligosaccharide are found in Golgi. N-linked oligosaccharide- are by far the most common oligosaccharidesfound in glycoprotein. (RER)are recognized by 2 ER charperon protein(calnexin & calreticulin)O-linked oligosaccharide are found in Golgi.
129Chapter 12 practice Roadmap of protein traffic Signal sequences & organelle targetingOrganelle epigenetic controlNuclear pore complex & nuclear import/export & its receptor/signalThe control of nuclear import during T-cell activationProtein translocation process in mitochondrial membrane: TOM, TIM, OXARelationship among import of mitochondrial precursor proteins, role of energy,its hsp70.Translocation of a precursor protein into the thylakoid space of chloroplasts.Peroxisomal enzymes & reactions, import mechanism distinct from mitochondria & chloroplast or unique character of peroxisomeSER, RER preparation, SRP, ribosome and RER protein transportCotranslation & postranlation translocation in bacteria, archea, and eucaryotesHydrophobicity of membrane protein and transmembrane domainProcess and role of protein N-link glycosylation in RERMembrane lipid bilayer assembly in ER: using example of phosphatidylcholine synthesisPhospholipid transport from ER to other organelles and comparison of ER and plasmamembrane