Microtubule motors

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Microtubulemotors
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Intracellulartransport vesicles
VSVG-GFP and Microtubules
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Fast Axonal Transport
Loligo
in vivo in vitro
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Freeze!
Transport vesicle
kinesin
microtubule
50 nm
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Biophysical analysis
Kinesin develops about 6 picoNewtons (pN) of force
8nm steps correspond to the spacing of tubulin
dimers
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Conventional KinesinTwo heads are better than
one!
ATP
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Kinesin model
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In vitro motility
Fluorescent microtubules gliding over a
kinesin-coated surface
Kinesin
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Biotech saddles the beast
A rectifying shape can direct traffic
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Kinesins share a conserved motor domain, placed
in different evolutionary contexts
100 nm
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Turning tail
400kDa Conventional Kinesin
Ionic strength (in vitro) Post-translational
modification?
Folding modulates interactions with microtubules
and cargo
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Kinesin in vitro motility assays
seed
Using polarity marked microtubules
-
Conventional kinesin is a plus-end directed motor
(minus-end of track leads)
Ncd is a kinesin that side steps in a weakly
minus-end directed motion to rotate the track
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Stepping out
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Kinesin family tree
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MAPs can block motor activity
Kinesin-driven anterograde movement of
mitochondria is blocked by ectopic expression of
MAPs like Tau
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Cytoplasmic dynein
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Adapting to a membrane
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Cytoplasmic dynein and b-COP
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Dynein inhibition causes outward dispersal of
lysosomes
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Dynein family tree
Spotty, perinuclear localization
Flagellar dyneins
Golgi localization
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Chlamydomonas
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Flagellar structure
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The flagellar dynein motor is (a) complex
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Microtubule sliding powers flagellar beating
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Sliding disintegration
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Dynein Mechanochemical Cycle
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Axonemal abnormalities
Normal
Kartageners syndrome
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Keeping the beat!
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Regulation
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Building the flagellum
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Microtubule commuters
kinesin
dynein