Kinesins are ATP-powered motor proteins that move along microtubules and help organize transport and other processes inside eukaryotic cells. This lesson introduces their discovery, the structure of a prototypical kinesin, and how motor activity is regulated.
The first kinesins were identified in 1985 as microtubule-based motors that carried material in the anterograde direction in cytoplasm from the giant axon of a squid. Researchers isolated kinesin-1 from neuronal cell extracts using its affinity for microtubules.
All flashcards
What is a kinesin?
A kinesin is an ATP-powered motor protein that moves along microtubules and supports cellular functions such as cargo transport and cell division.
What is the composition of kinesin-1?
Kinesin-1 is a heterotetramer consisting of two identical kinesin heavy chains and two kinesin light chains.
What does the kinesin motor domain do?
The globular head binds a microtubule and ATP. Nucleotide-driven structural changes help coordinate binding and stepping.
What is the role of the kinesin stalk?
The coiled-coil stalks of two heavy chains intertwine, supporting dimerization of the motor.
How can kinesin self-inhibition be relieved?
In some kinesins, the tail interacts with the motor domain to inhibit activity. Cargo, cargo adapters, or other microtubule-associated proteins can relieve this inhibition.
Quiz questions
In what year were the first kinesins identified as microtubule-based transport motors?Answer: 1985
What subunits make up kinesin-2?Answer: Two distinct KHC-related motor subunits and one accessory KAP subunit
What is a role of kinesin-5 proteins during mitosis?Answer: Sliding spindle microtubules apart
What effect can kinesin-13 proteins have on microtubules?Answer: They can promote microtubule depolymerization.
In a class of kinesin models, what behavior is recovered when the motor-interaction term is set to zero?Answer: Totally asymmetric simple exclusion process behavior
Based on the Wikipedia article Kinesin, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.