cell molc lesson 8

microtubule building block

alpha/beta tubulin-dimer

microtubule nucleotide that building blocks bind

GTP

microtubule motor proteins

kinesin (- to +), dynein (+ to -)

microfilament building block

g-actin

microfilament nucleotide that building block binds

ATP

microfilament motor protein

myosin

motor energy for microfilament and microtubule

ATP

dynamic cytoskeleton components

microfilament and microtubule

polarized cytoskeleton components

microfilament and microtubule

neurofilament building block

NFH/M/L

neurofilaments (intermediate filaments)

most abundant in axons (axonal marker)

anterograde transport

cell body to axon terminal, driven by kinesin in axons

retrograde transport

axon terminal to cell body, driven by dyneins in axons

microtubule orientation in axons

uniform polarity, + point toward axon terminal, - end points toward soma

microtubule orientation in dendrites

mixed polarity; kinesins and dyneins can drive both transports

microtubule binding protein in axons

tau, stabilizes microtubules

microtubule binding protein in dendrites

MAP2, dendritic marker

treadmilling

+ end of a filaments grows in length while the - end shrinks, filament length stays the same, occurs at critical concentration in microtubules and microfilaments

microfilament function at the synapse

scaffold for vesicles in presynaptic compartments, support the AMPAR/NMDAR and RNP trafficking in postsynaptic compartments, structural support for both pre and post synaptic compartments

neurofilament function in axon diameters

charged tails determine diameter of axon; phosphorylated (-) NFM and NFH tails repel each other

cre recombinase

catalyzes recombination between loxP sites

Cre/LoxP + tet-on

rtTa binds to dox → binds to promoter → cre expression → loxP recombines → gene deleted

Cre/LoxP

controls where (tissue specific promoter)

tet-on

controls when (dox dependent)

Cre/LoxP + tet-off

tTa binds to promoter → cre expressed → gene deleted (when dox there → inhibits cre expression)

loxP sites in same direction (→ →)

gene deletion

loxP sites in opposite directions (→ ←)

gene inverted