BCOR 103 1st Edition Lecture 9Outline of Last Lecture I. The CytoskeletonII. Cytoskeletal StructuresIII. Filament AssemblyIV. Dynamic InstabilityOutline of Current Lecture I. Microtubule Associated Proteins (MAPs)II. Kinesin and Dynein III. Structure and Function of Actin IV. Motor ProteinsCurrent LectureThere are seven different MAPs that should be known. The first is γ-tubulin ring complex which initiates the formation of a microtubule. The second MAP to know is XMAP215 which polymerizes the (+) end of the microtubule. Next is Kinesins 8 and 13 which depolymerize the (+) end of the microtubule. CLASP and EB1 controls (+) tracking. Katanin controls severing the microtubule. Tau, MAP1, MAP2, and MAP4 work to stabilize the microtubule lengthwise. Lastly, CLASP is also involved in rescue functions of the microtubules. Kinesin is made up of two “heavy chains” and “light chains” connected by an alpha helix. The heavy chains are two globular proteins that attach to the microtubule. The light chains attach tothe vesicle or protein being transported within the cell. The kinesin works with ATP to move its proteins along the microtubule in the direction toward the positive end of the microtubule. Dynein serve a similar function to kinesin, except it moves its materials toward the negative endof the microtubule. Dynein also has a different structure from kinesin. Dynein has two heavy chains that link with the microtubule, but the other side is made up of lots of light chains, approximately seven. The light chains bond with the material being moved and the other heavychains move along the microtubule. G actin is the molecule that actin fibers are made up of. Actin monomers (G actin) come together to form dimers, then trimers, and eventually a microfilament with a positive and negative end. These microfilaments layer together called monomer polymerizing. The dimer “formin” can regulate the (+) end of the microfilament. Actin works with the motor proteins These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.that are microfilament based “myosin.” There are many different types of myosin proteins. We will focus on the mechanism. The myosin head that is connected to a microfilament works in tandem with ATP to attach and release to a parallel actin filament. Myosin uses ATP to move up actin. This is primarily seen in muscles, it is how they
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