12-11-09_ActinMyosinreviewA

_ActinMyosin - It is the cells which create and maintain in us during the span of our lives our will to live and survive to search and experiment

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
It is the cells which create and maintain in us, during the span of our lives, our will to live and survive, to search and experiment, and to struggle. Albert Claude For over two billion years, through the apparent fancy of her endless differentiations and metamorphosis the Cell, as regards its basic physiological mechanisms, has remained one and the same. It is life itself, and our true and distant ancestor. Albert Claude I was thinking about how people seem to read the Bible a whole lot more as they get older; then it dawned on me – they’re cramming for the final exam – George Carlin Always do whatever’s next – George Carlin
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Announcements Please complete online course evaluations by December 13 My office hours will be 9-10 AM Monday and Tuesday next week Answers to review questions will be sent out today
Background image of page 2
Structure of kinesin Involved in anterograde transport of materials (towards plus- end of microtubules) Tetramer consisting of two heavy chains and two light chains with a head, neck/stalk, tail structure Head is force generating side Tail is cargo binding side Best studied microtubule motor. Found in high concentration in axons and initially isolated from squid giant axon.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Kinesin mechanochemical cycle At the start of the cycle, the leading head (dark green) is bound to the microtubule. The trailing head (light green) is detached and bound to ADP. Binding of ATP to the front head causes a major conformational change. The rear head is thrown forward, past the binding site of the attached head, to another binding site further toward the plus end of the MT. Release of ADP from the second head (now in the front) and hydrolysis of ATP on the first head (now in the rear) brings the dimer back to the original state The two heads have switched their relative positions, and the motor protein has moved one dimer step along the microtubule protofilament. Alberts et al.
Background image of page 4
Going retro: the dynein motor First MT-associated motor found (1963). Responsible for moving cilia & flagella & was called dynein; Huge protein (~1.5 million daltons); made of 2 identical heavy chains & Each dynein heavy chain consists of large globular head with 2 elongated projections (~10X larger than a kinesin head); The head acts as a force-generating engine The stalk contains the MT-binding site situated at its tip The stem binds the intermediate & light chains, which are implicated in attachment to various types of cargo Binds to MTs Binds to cargo or dynactin
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/09/2010 for the course BIOL 230 taught by Professor Bartlett,e during the Fall '08 term at Purdue University-West Lafayette.

Page1 / 26

_ActinMyosin - It is the cells which create and maintain in us during the span of our lives our will to live and survive to search and experiment

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online