Drugs and Buffers

For successful in vitro research on cytoskeletal components, it is vital to use the right buffers. For example, myosin and kinesin ATPase activity is highly dependent on the buffer components having less than 75mM ionic strength, above that concentration and the motor starts to dissociate from the polymer (F-actin or microtubules). Cytoskeleton provides a selection of microtubule and actin buffers for these assays.


Cytoskeleton's motor protein products have been cited hundreds of times over the past 18 years. A select few are described here, for more citations on individual products please use the "Citations" tab on each individual product page.


Phalloidin (rhodamine): 14uM (Cat. # PHDR1)

Ezratty, E. J., Partridge, M. A. and Gundersen, G. G. (2005). Microtubule-induced focal adhesion disassembly is mediated by dynamin and focal adhesion kinase. Nat. Cell Biol. 7, 581-590.
Gomes, E. R., Jani, S. and Gundersen, G. G. (2005). Nuclear movement regulated by Cdc42, MRCK, myosin, and actin flow establishes MTOC polarization in migrating cells. Cell 121, 451-463.
Chandhoke, S. K., Williams, M., Schaefer, E., Zorn, L. and Blystone, S. D. (2004). β3 integrin phosphorylation is essential for Arp3 organization into leukocyte αVβ3-vitronectin adhesion contacts. J. Cell Sci. 117, 1431-1441.
Hsieh-Wilson, L. C., Benfenati, F., Snyder, G. L., Allen, P. B., Nairn, A. C. and Greengard, P. (2003). Phosphorylation of spinophilin modulates its interaction with actin filaments. J. Biol. Chem. 278, 1186-1194.
Qian, Y., Baisden, J. M., Cherezova, L., Summy, J. M., Guappone-Koay, A., Shi, X., Mast, T., Pustula, J., Zot, H. G., Mazloum, N. et al. (2002). PKC phosphorylation increases the ability of AFAP-110 to cross-link actin filaments. Mol. Biol. Cell 13, 2311-2322.
Chen, J., Fabry, B., Schiffrin, E. L. and Wang, N. (2001). Twisting integrin receptors increases endothelin-1 gene expression in endothelial cells. Am J Physiol Cell Physiol 280, C1475-1484.

Paclitaxel: 2mM (Cat. # TXD01)

 Kosturko, L. D., Maggipinto, M. J., D'Sa, C., Carson, J. H. and Barbarese, E. (2005). The microtubule-associated protein tumor overexpressed gene binds to the RNA trafficking protein heterogeneous nuclear ribonucleoprotein A2. Mol. Biol. Cell 16, 1938-1947.
Teckchandani, A. M., Birukova, A. A., Tar, K., Verin, A. D. and Tsygankov, A. Y. (2005). The multidomain protooncogenic protein c-Cbl binds to tubulin and stabilizes microtubules. Exp. Cell Res. 306, 114-127.
Nair, K. S., Hanson, S. M., Kennedy, M. J., Hurley, J. B., Gurevich, V. V. and Slepak, V. Z. (2004). Direct binding of visual arrestin to microtubules determines the differential subcellular localization of its splice variants in rod photoreceptors. J. Biol. Chem. 279, 41240-41248.
Wagner, O. I., Ascano, J., Tokito, M., Leterrier, J. F., Janmey, P. A. and Holzbaur, E. L. (2004). The interaction of neurofilaments with the microtubule motor cytoplasmic dynein. Mol. Biol. Cell 15, 5092-5100
Ligon, L. A., Shelly, S. S., Tokito, M. and Holzbaur, E. L. (2003). The microtubule plus-end proteins EB1 and dynactin have differential effects on microtubule polymerization. Mol. Biol. Cell 14, 1405-1417.
Benink, H. A., Mandato, C. A. and Bement, W. M. (2000). Analysis of cortical flow models in vivo. Mol. Biol. Cell 11, 2553-2563.
 Korinek, W. S., Copeland, M. J., Chaudhuri, A. and Chant, J. (2000). Molecular linkage underlying microtubule orientation toward cortical sites in yeast. Science 287, 2257-2259.

Question 1:  What is a good control compound for inhibiting kinesin motor proteins?

Answer 1:  Unfortunately, only a limited number of kinesin inhibitors exist.  A general ATP-site inhibitor can be a non-hydrolyzable ATP analog e.g. AMPPNP.  These give excellent inhibition as presented in Funk et al., 2004 (Development of high-throughput screens for discovery of kinesin adenosine triphosphatase modulators. Anal Biochem. 329, 68-76).  Another well-utilized inhibitor is monastrol which inhibits Eg5.  Monastrol is a reversible, cell-permeable, non-tubulin interacting inhibitor of the mitotic kinesin Eg5 motor protein.  In some situations the antibodies to the motor proteins can be used to inhibit motor functions.  This would need to be determined empirically.


Question 2:  Do you sell any full length kinesins or ones that have microtubule motility?

Answer 2: Unfortunately, we do not sell any full length kinesins.  However, we sell many purified kinesin motor domain proteins, including Cat. # CP01(CENP-E), CR01 (Chromokinesin), EG01(Eg5), BM01 (Eg5 homolog BimC from A. nidulans), EG02 (Eg5 homolog BimC from A. fumigatus), KC01 (KIFC3), KF01 (KIF3C), KR01 (kinesin heavy chain), MK01 (MCAK) and MP01 (MKLP).  For microtubule motility studies, we recommend kinesin heavy chain motor domain protein (Cat. # KR01).  We offer this motor protein, rhodamine-labeled tubulin, unlabeled tubulin, antifade solution, ATP (Cat. # BSA04-001), microtubule cushion buffer, general tubulin buffer (Cat. # BST01-001), blocking solution, chamber wash buffer, kinesin buffer, taxol (Cat. # TXD01), DMSO, perfusion chamber filter paper and acid-washed perfusion chambers in a convenient kit format (Cat. # BK027).   The kinesin heavy chain motor (Cat. # KR01) can serve as a positive control in this kit when studying an uncharacterized motor protein or as a substrate to examine how a drug/compound affects kinesin/microtubule motility.


For more information, click on the Documents tab above to see the datasheet, or contact Technical Support at tservice@cytoskeleton.com.