Purification and characterization of beta-actin-rich tumor cell pseudopodia: role of glycolysis.
The MSV-MDCK-INV invasive variant of Moloney sarcoma virus (mos) transformed MDCK cells express multiple beta-actin-rich pseudopodia (P. U. Le et al., Cancer Res. 58, 1631-1635, 1998). We show here that the tips of these actively protruding cellular domains are morphologically distinct presenting numerous blebs and selectively pass through 1-microm-pore filters. The pseudopodia were purified from the underside of the filters and a major protein component was identified as the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). By confocal microscopy, GAPDH colocalized with actin in MSV-MDCK-INV pseudopodia localizing this glycolytic enzyme to this site of active actin polymerization. Inhibition of glycolysis with 2-deoxyglucose or oxamate induced a rapid transformation of beta-actin-rich pseudopodia into extended lamellipodia and prevented cell motility. A localized glycolytic supply of energy therefore regulates the formation of beta-actin-rich pseudopodial protrusions and thereby the motility of invasive tumor cells.
Département de Pathologie et Biologie Cellulaire, Université de Montréal, Québec, Canada.
T N
TN
Nguyen
H J
HJ
Wang
S
S
Zalzal
A
A
Nanci
I R
IR
Nabi
D000199:Actins / Q000032:analysis*; D000818:Animals; D002458:Cell Fractionation; D002461:Cell Line, Transformed; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic; D004285:Dogs; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis; D006019:Glycolysis; D007668:Kidney; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000378:metabolism; D008980:Moloney murine sarcoma virus / Q000502:physiology*; D010101:Oxygen Consumption; D011554:Pseudopodia / Q000473:pathology / Q000648:ultrastructure*
D000199:Actins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases