Abstract
We have identified a novel mechanism of cross-talk between cell signaling and metabolic pathways, whereby the signaling kinase p21-activated kinase 1 (Pak1) binds to, phosphorylates and enhances the enzymatic activity of phosphoglucomutase 1 (PGM), an important regulatory enzyme in cellular glucose utilization and energy homeostasis. Pak1 and PGM were colocalized in model cell systems and showed functional interactions in a physiological setting. Strong direct interaction of PGM with Pak1 but not Pak2, Pak3, or Pak4 was observed. PGM binding was within 75-149 amino acids (aa) of Pak1, while Pak1 binding to PGM was in the N-terminal 96aa. Pak1-mediated phosphorylation of PGM selectively on threonine 466 significantly increased PGM enzymatic activity and could be blocked by transfection with a dominant-negative Pak1 expression vector and by Pak1-specific small inhibitory RNA. Stable transfection of PGM into PGM-deficient K-562 leukemia cells further demonstrated the role of Pak1 in regulating PGM activity. The results presented here provide new evidence that the cell signaling kinase Pak1 is a novel regulator of glucose metabolism through its phosphorylation and regulation of PGM activity. These findings suggest a new mechanism whereby growth factor signaling may coordinately integrate metabolic regulation with established signaling functions of cell cycle regulation and cell growth.
Original language | English (US) |
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Pages (from-to) | 8118-8127 |
Number of pages | 10 |
Journal | Oncogene |
Volume | 23 |
Issue number | 49 |
DOIs | |
State | Published - Oct 21 2004 |
Externally published | Yes |
Keywords
- Cancer metabolism
- Glycolysis
- PGM
- Signaling
ASJC Scopus subject areas
- Molecular Biology
- Genetics
- Cancer Research