Dynamic compartmentalization of purine nucleotide metabolic enzymes at leading edge in highly motile renal cell carcinoma

Biochem Biophys Res Commun. 2019 Aug 13;516(1):50-56. doi: 10.1016/j.bbrc.2019.05.190. Epub 2019 Jun 10.


Compartmentalization is vital for biological systems at multiple levels, including biochemical reactions in metabolism. Organelle-based compartments such as mitochondria and peroxisomes sequester the responsible enzymes and increase the efficiency of metabolism while simultaneously protecting the cell from dangerous intermediates, such as radical oxygen species. Recent studies show intracellular nucleotides, such as ATP and GTP, are heterogeneously distributed in cells with high concentrations at the lamellipodial and filopodial projections, or leading edge. However, the intracellular distribution of purine nucleotide enzymes remains unclear. Here, we report the enhanced localization of GTP-biosynthetic enzymes, including inosine monophosphate dehydrogenase (IMPDH isotype 1 and 2), GMP synthase (GMPS), guanylate kinase (GUK1) and nucleoside diphosphate kinase-A (NDPK-A) at the leading edge in renal cell carcinoma cells. They show significant co-localization at the membrane subdomain, and their co-localization pattern at the membrane is distinct from that of the cell body. While other purine nucleotide biosynthetic enzymes also show significant localization at the leading edge, their co-localization pattern with IMPDH is divergent. In contrast, a key glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), predominantly localized in the cytoplasm. Mechanistically, we found that plasma membrane localization of IMPDH isozymes requires active actin polymerization. Our results demonstrate the formation of a discrete metabolic compartment for localized purine biosynthesis at the leading edge, which may promote localized nucleotide metabolism for cell migration and metastasis in cancers.

Keywords: GMPS; GUK1; IMPDH; Metabolic compartmentalization; Salvage purine synthesis; de novo purine synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon-Nitrogen Ligases / analysis
  • Carbon-Nitrogen Ligases / metabolism
  • Carcinoma, Renal Cell / enzymology*
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • Cell Line, Tumor
  • Guanylate Kinases / analysis
  • Guanylate Kinases / metabolism
  • Humans
  • IMP Dehydrogenase / analysis
  • IMP Dehydrogenase / metabolism
  • Kidney Neoplasms / enzymology*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • NM23 Nucleoside Diphosphate Kinases / analysis
  • NM23 Nucleoside Diphosphate Kinases / metabolism
  • Purine Nucleotides / metabolism*


  • NM23 Nucleoside Diphosphate Kinases
  • Purine Nucleotides
  • IMP Dehydrogenase
  • Guanylate Kinases
  • Carbon-Nitrogen Ligases
  • GMP synthase (glutamine-hydrolyzing)