Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. STKE, 18 December 2001
Vol. 2001, Issue 113, p. tw463
[DOI: 10.1126/stke.2001.113.tw463]


Cell Biology Network Hopping by PAK

The p21-activated kinases (PAKs) mediate the effects of Rho family proteins CDC42 and Rac on the actin cytoskeleton during processes such as cell migration. Cau et al. have now identified a PAK family member that modulates the microtubule (MT) network of cells as well. Ectopically expressed Xenopus PAK (X-PAK5) bound to newly formed MTs that nucleated from the centrosome of cultured Xenopus cells. Binding did not require X-PAK5 catalytic activity, and the interaction stabilized MTs, which appeared thick and curly. The X-PAK5-MT interaction also caused a pause in MT dynamics, where neither growth nor shrinkage occurred, a mechanism that could facilitate the development of a fully spread MT network. Overexpression of a constitutively active form of X-PAK5 caused a loss of the curly MT phenotype, but also induced cell-body retraction and the extension of numerous, actin-rich filipodia. In addition, constitutively activated X-PAK5 relocalized from MTs to actin-rich filopodia and lamellipodia. Although expression of constitutively active CDC42 or Rac did not activate X-PAK5, it caused a similar relocalization of X-PAK5 to actin-rich structure. Just how this PAK family member jumps from one cell structural network to another remains to be determined.

J. Caum, S. Fauré, M. Comps, C. Delsert, N. Morin, A novel p21-activated kinase binds the actin and microtubule networks and induces microtubule stabilization. J. Cell Biol. 155, 1029-1042 (2001). [Abstract] [Full Text]

Citation: Network Hopping by PAK. Sci. STKE 2001, tw463 (2001).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882