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25 Cards in this Set
- Front
- Back
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signal sequence
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short sequence of AA
can be within the protein or at the terminal ends |
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Signal patch
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made up of AA residues that are distant to one another , but come close to each other int he tertiary structure (folded)
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sugar molecules
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specific sugar moelcules can act as a localization signal
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what is expected of a sorting signal?
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necessary and sufficient
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what does it mean by Necessary
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it should direct a protein into a new membrane-enclsoed compartment
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what does it mean by sufficient?
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it should direct a neutral protein without sorting information to the new environment
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what are some considerations for transport of a protein to its destined location?
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sorting signal
specific receptor translocation machinery translocation competent state release energy folding/processing |
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where are tom protein located?
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outer membrane
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where are tim proteins located?
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inner membrane
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what binds to the protein as it enter the mito matrix to prevent premature folding?
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HSC 70
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what does the mitochondrial uptake signal look like?
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signal at the N terminus
20-50aa in lenght Arg, Lys (+) on one side of helixx hydrophobic aa on other side helix |
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what drives protein import into mitochondria?
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ATP required to remove hsp70
H+ gradient promotes the translocation of proteins w/ a positively charged signal sequence ATP-dependent pulling of the substrate protein by Hsp70 |
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are independent sorting signals required for every transport step?
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YES
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How can a protein get into the inner mito membrane?
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2 mechanisms
Mech 1: |
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NLS
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transports in(import) of nucleus
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NES
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nuclear export sequence
transport out(export) of the nucleus |
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Which layer defines the nucleus?
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inner nuclear membrane
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what layer of the nucleus is continues with ER
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outer nuclear membrane
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what is the site of protein and RNA transport into and out of the nucleus?
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Nuclear Pore - its constitutively open but still requires NLS
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is the NLS sequence neccessary, sufficient, both, or neither?
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both
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what are importins?
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move protein through the pore, even in a fully folded state
RECEPTOR |
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what is the transport machinery for nuclear import?
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nuclear pore
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what is the driving force for nuclear import?
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GTP-Ran binding
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what is RAN
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ran is a small GTPase
monomeric exists in GTP-bound and GDP-bound |
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GAP
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GTPase activating protein
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