Metabolic compartmentation in living cells: structural association of aldolase.
The glycolytic enzyme aldolase is concentrated in a domain around stress fibers in living Swiss 3T3 cells, but the mechanism by which aldolase is localized has not been revealed. We have recently identified a molecular binding site for F-actin on aldolase, and we hypothesized that this specific binding interaction, rather than a nonspecific mechanism, is responsible for localizing aldolase in vivo. In this report, we have used fluorescent analog cytochemistry of a site-directed mutant of aldolase to demonstrate that actin-binding activity localizes this molecule along stress fibers in quiescent cells and behind active ruffles in the leading edge of motile cells. The specific cytoskeletal association of aldolase could play a structural role in cytoplasm, and it may contribute to metabolic regulation, metabolic compartmentation, and/or cell motility. Functional duality may be a widespread feature among cytosolic enzymes.
Wang
J
J
Center for Bioengineering, University of Washington, Seattle 98195, USA. jianwang@andrew.cmu.edu
Tolan
D R
DR
Pagliaro
L
L
D016475:3T3 Cells; D008841:Actin Cytoskeleton / Q000201:enzymology; D000199:Actins / Q000378:metabolism; D000818:Animals; D002451:Cell Compartmentation; D003599:Cytoskeleton / Q000201:enzymology*; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D051379:Mice; D008845:Microinjections; D008856:Microscopy, Fluorescence; D013329:Structure-Activity Relationship; D014783:Viscosity
D000199:Actins; D005634:Fructose-Bisphosphate Aldolase