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Published byPrimrose Bruce Modified over 9 years ago
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Telomeres special sequences at chromosome ends special proteins protect them
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Telomeres special sequences at chromosome ends special proteins protect them can't copy 5' end of lagging strand since remove primer
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Telomeres can't copy 5' end of lagging strand since remove primer telomeres lose ~ 200 bp/S
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Telomeres can't copy 5' end of lagging strand since remove primer telomeres lose ~ 200 bp / S telomerase replaces them
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Telomerase telomeres lose ~ 200 bp / S telomerase replaces them reverse transcriptase with attached RNA template
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Telomerase telomeres lose ~ 200 bp each S telomerase replaces missing bases reverse transcriptase with attached RNA template 1) RNA bonds leading strand
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Telomerase reverse transcriptase with attached RNA template 1) RNA bonds leading strand 2) Forms template to extend leading strand
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Telomerase reverse transcriptase with attached RNA template 1) RNA bonds leading strand 2) Forms template to extend leading strand 3) Translocates 6 bases & repeats
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Telomerase reverse transcriptase with attached RNA template 1) RNA bonds leading strand 2) Forms template to extend leading strand 3) Translocates 6 bases & repeats 4) Extend lagging strand with primer & DNA pol
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Telomeres Aging theory:” mature” cells lose telomerase
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each S
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each S Die when lose too much
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each S Die when lose too much Cancer cells reactivate telomerase
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each cell cycle Die when lose too much Cancer cells reactivate telomerase [serum telomerase] can diagnose cancer
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each S Die when lose too much Cancer cells reactivate telomerase [serum telomerase] can diagnose cancer Inhibiting telomerase kills cancer cells
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Telomeres Aging theory:” mature” cells lose telomerase lose DNA each S Die when lose too much Cancer cells reactivate telomerase [serum telomerase] can diagnose cancer Inhibiting telomerase kills cancer cells Telomerase is symptom cf cause of cancer
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Regulating E3 ligases The COP9 signalosome (CSN), a complex of 8 proteins, regulates E3 ligases by removing Nedd8 from cullin
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Regulating E3 ligases The COP9 signalosome (CSN), a complex of 8 proteins, regulates E3 ligases by removing Nedd8 from cullin CAND1 then blocks cullin
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Regulating E3 ligases The COP9 signalosome (CSN), a complex of 8 proteins, regulates E3 ligases by removing Nedd8 from cullin CAND1 then blocks cullin Ubc12 replaces Nedd8
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Regulating E3 ligases The COP9 signalosome (CSN), a complex of 8 proteins, regulates E3 ligases by removing Nedd8 from cullin CAND1 then blocks cullin Ubc12 replaces Nedd8 Regulates DNA-damage response, cell-cycle & gene expression
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Regulating E3 ligases The COP9 signalosome (CSN), a complex of 8 proteins, regulates E3 ligases by removing Nedd8 from cullin CAND1 then blocks cullin Ubc12 replaces Nedd8 Regulates DNA-damage response, cell-cycle & gene expression Not all E3 ligases associate with Cullins!
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COP1 is a non-cullin-associated E3 ligase Protein degradation is important for light regulation COP1/SPA1 tags transcription factors for degradation W/O COP1 they act in dark In light COP1 is exported to cytoplasm so TF can act
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COP1 is a non-cullin-associated E3 ligase Recent data indicates that COP1 may also associate with CUL4
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Protein degradation rate varies 100x Most have motifs marking them for polyubiquitination : taken to proteosome & destroyed Other signals for selective degradation include PEST & KFERQ PEST : found in many rapidly degraded proteins e.g. ABCA1 (which exports cholesterol in association with apoA-I) is degraded by calpain
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Protein degradation rate varies 100x Other signals for selective degradation include PEST & KFERQ PEST : found in many rapidly degraded proteins e.g. ABCA1 (which exports cholesterol in association with apoA-I) is degraded by calpain Deletion increases t 1/2 10x, adding PEST drops t 1/2 10x
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Protein degradation rate varies 100x Other signals for selective degradation include PEST & KFERQ PEST : found in many rapidly degraded proteins e.g. ABCA1 (which exports cholesterol in association with apoA-I) is degraded by calpain Deletion increases t 1/2 10x, adding PEST drops t 1/2 10x Sometimes targets poly-Ub
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Protein degradation rate varies 100x Other signals for selective degradation include PEST & KFERQ PEST : found in many rapidly degraded proteins e.g. ABCA1 (which exports cholesterol in association with apoA-I) is degraded by calpain Deletion increases t 1/2 10x, adding PEST drops t 1/2 10x Sometimes targets poly-Ub Recent yeast study doesn’t support general role
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Protein degradation rate varies 100x Other signals for selective degradation include PEST & KFERQ PEST : found in many rapidly degraded proteins e.g. ABCA1 (which exports cholesterol in association with apoA-I) is degraded by calpain Deletion increases t 1/2 10x, adding PEST drops t 1/2 10x Sometimes targets poly-Ub Recent yeast study doesn’t support general role KFERQ: cytosolic proteins with KFERQ are selectively taken up by lysosomes in chaperone-mediated autophagy under conditions of nutritional or oxidative stress.
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