Term
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Definition
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Term
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Definition
| motor proteins of microtubules |
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Term
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Definition
- Actin binding
- ATP binding
- ATPase activity
- Actin-activated ATPase |
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Term
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Definition
- dictates step size
- dictates movement rate
- bind Myosin Light Chains |
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Term
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Definition
membrane association, endocytosis
- monomer(variable)
- (+)end direction
- NOT processive
- 10-14 nm step size
- vesicle transport, membrane tension
- single-headed myosin
- tail domains bind to membrane lipids
- eight vertebrate members of the myosin I family
- associates with zymogen granules |
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Term
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Definition
contraction
- dimer (2)
- (+)end direction
- NOT processive
- 8 nm step size
- tension (imparts tension on stress fibers)
- activated by Ca2+ |
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Term
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Definition
organelle transport
- dimer (6)
- (+)end direction
- processive
- 37 nm step size
- vesicle transport |
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Term
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Definition
- dimer
- (-)end direction
- processive
- vesicle transport
- Renal Proximal Tubules - base of microvilli |
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Term
| Why a non-processive, short duty cycle? |
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Definition
| Allows for a fast, smooth muscle contraction. |
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Term
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Definition
| the positive ends are oriented towards the z disk (bound to CapZ) and the negative end is bound with tropomodulin. Muscle myosin II is activated by calcium because you can't wait for kinase activity (too slow). In the absence of calcium, you have tropomyosin and troponin covering the binding sites on actin for myosin. Myosin II doesn't hold onto the actin after it takes a step, so the movement is back and forth. Myosin V holds on after a step and creates a progressive movement |
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Term
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Definition
Myosin V gene
- neurons/melanocytes
- vesicle transport |
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Term
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Definition
Myosin V gene
- epithelia
- vesicle transport |
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Term
| Griscelli Syndrome type I |
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Definition
MyoVa mutations
- partial albinism (silver hair) (loss of melanosome function)
- neurologic deficits
- manifest very early in children |
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Term
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Definition
Microtubule Motor Protein
- 45 family members (humans)
- (+) end directed motors
- anterograde
- functions as dimers
- processive motors
- hydrolyze ATP |
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Term
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Definition
Microtubule Motor Proteins
- 19 family members (humans)
- (-)end directed motors
- retrograde
- functions as dimers
- processive motors
- hydrolyze ATP
- two types: cytoplasmic and axonemal |
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Term
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Definition
organelle transport
- tetramer: 2 heavy and 2 light chains
- MW ~ 380 kDa
- head domain: motor (globular), binds/hydrolyzes ATP
- linker domain: flexible
- stalk domain: long (dimerization)
- tail domain: cargo-binding (globular)
- direction: (+)end directed
- motor: PROCESSIVE
- 8 nm step size
- 16 nm swing size |
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Term
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Definition
- binding to cargo
- phosphorylation of the light chain |
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Term
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Definition
- tubulin binding site
- stalk domain
- may act as the motor's lever
- motor domain
- 6 AAA domains arranged in a ring
- stem domain
- coiled-coil sequences: dimerization
- binding of dynein intermediate chains
- binding of "cargo" (indirect) |
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Term
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Definition
- 2 heavy chains
- multiple
- intermediate chains
- light intermediate chains
- light chains
- Binds DYNACTIN complex = "cargo" binding |
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Term
| Evolving Mechanisms for Bi-directional transport |
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Definition
A. Kinesins and Dyneins come on/off
B. Kinesins and Dyneins co-reside
C. Kinesins and Dyneins co-reside and are co-regulated |
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