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, 6 December 2005
Vol. 2005, Issue 313, p. tw432
[DOI: 10.1126/stke.3132005tw432]

EDITORS' CHOICE

BIOCHEMISTRY New Role for 14-3-3

Al-Hakim et al. explored regulation of members of the adenosine monophosphate-activated protein kinase (AMPK) family by a tandem affinity purification procedure that isolated proteins that interacted with the enzymes in cultured human embryonic kidney cells. They identified a number of new interaction partners, including the phosphoprotein-binding adaptor 14-3-3. The 14-3-3 protein interacted with the kinases QSK and SIK (salt-inducible kinase) in a manner that required their previous phosphorylation by their activating kinase LKB1. When glutathione S-transferase (GST) fusion proteins of QSK and SIK were expressed in 293 cells and affinity purified, 14-3-3 was associated with them. Displacement of 14-3-3 during incubation with a competing phosphopeptide decreased the catalytic activity of the kinases. Experiments in cells lacking LKB1 indicated that binding to 14-3-3 promoted cytoplasmic localization of QSK and SIK. Such control of protein localization is a known function of 14-3-3, but the protein has not previously been shown to directly modulate catalytic activity of its binding partners. The authors suggest that the 14-3-3 protein may work by simultaneously binding the kinases and their substrate proteins.

A. K. Al-Hakim, O. Göransson, M. Deak, R. Toth, D. G. Campbell, N. A. Morrice, A. R. Prescott, D. R. Alessi, 14-3-3 cooperates with LKB1 to regulate the activity and localization of QSK and SIK. J. Cell Sci. 118, 5661-5673 (2005). [Abstract] [Full Text]

Citation: New Role for 14-3-3. Sci. STKE 2005, tw432 (2005).



To Advertise     Find Products


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