Inosine-5′-monophosphate dehydrogenase

Inosine-5′-monophosphate dehydrogenase (IMPDH) is an essential cytoplasmic purine metabolic enzyme that catalyzes the NAD-dependent oxidation of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), the first and rate-limiting step towards the synthesis of GTP from IMP. IMPDH has an essential role in providing precursors for DNA and RNA bioysynthesis. IMPDH also plays a role in signal transduction pathways that mediate cell differentiation. As purine metabolism is largely conserved across all known organisms, so is the structure and function of IMPDH. IMPDH from pathogenic bacterium Streptococcus pyogenes to human crystallizes as a tetramer[1].

IMPDH expression is found to be upregulated in tumor tissues and tumor cell lines[2][3]. Accordingly, human IMPDH is a target of clinical anti-cancer drugs, in particular mycophenolic acid[4], which is also a widely used immuno-depressor. In murine cells, p53-dependent growth suppression requires down-regulation of IMPDH[5].

EC 1.1.1.205

See also

References

  1. ^ . http://www.ncbi.nlm.nih.gov/pubmed/10200156. 
  2. ^ . http://cancerres.aacrjournals.org/content/52/20/5826.abstract. 
  3. ^ . http://www.ncbi.nlm.nih.gov/pubmed/9752721. 
  4. ^ . http://www.ncbi.nlm.nih.gov/pmc/articles/PMC25212/. 
  5. ^ . http://cancerres.aacrjournals.org/content/43/8/3466.long. 
Purine metabolism
Anabolism

R5P→IMP: R5P · PRPP · PRA · GAR · FGAR · FGAM · AIR · CAIR · SAICAR · AICAR · FAICAR

IMP→AMP: Adenylosuccinate

IMP→GMP: Xanthosine monophosphate
Catabolism
Pyrimidine metabolism
Anabolism
Catabolism

M: MET

mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m

k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon

m(A16/C10),i(k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)
biochemical families: prot · nucl · carb (glpr, alco, glys) · lipd (fata/i, phld, strd, gllp, eico) · amac/i · ncbs/i · ttpy/i