{"entity":{"id":"impdh2","kind":"target","name":"IMP dehydrogenase (IMPDH2)","aka":[],"tldr":"IMPDH is the bottleneck enzyme for making guanine nucleotides; mycophenolate blocks it to hold back the donor T cells that cause graft-versus-host disease after stem cell transplantation, and the enzyme is over-expressed in fast-growing tumours.","summary":"Inosine monophosphate dehydrogenase catalyses the rate-limiting step of guanine nucleotide synthesis, and the type 2 isoform is induced in proliferating lymphocytes and in many cancers. Mycophenolate mofetil, a prodrug of the IMPDH inhibitor mycophenolic acid, is used with a calcineurin inhibitor to prevent graft-versus-host disease after allogeneic stem cell transplantation, and IMPDH is also the target of the old antileukaemic drug tiazofurin and part of the action of ribavirin. Because glioblastoma, small-cell lung cancer and other tumours depend on IMPDH2 for nucleotide supply, repurposing mycophenolate as an anticancer agent is in early trials.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/IMP_dehydrogenase","links":[{"label":"UniProt P12268: IMPDH2","url":"https://www.uniprot.org/uniprotkb/P12268/entry"},{"label":"HGNC:6053 IMPDH2","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6053"},{"label":"ChEMBL target CHEMBL2111369","url":"https://www.ebi.ac.uk/chembl/explore/target/CHEMBL2111369"}],"tags":["chembl-gap"],"related":["dhfr","gart"],"cancers":["glioblastoma","sclc"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["gvhd"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"symbol":"IMPDH2","biology":"A tetrameric NAD-dependent dehydrogenase that oxidises IMP to XMP; lymphocytes rely on this de novo route because they lack an efficient guanine salvage pathway.","whereFound":["Activated lymphocytes","Glioblastoma, small-cell lung cancer and other rapidly dividing tumours"],"targetClass":"enzyme","prevalence":[]},"route":"/targets/impdh2/","neighbours":{"target":[{"id":"dhfr","kind":"target","name":"Dihydrofolate reductase (DHFR)","route":"/targets/dhfr/"},{"id":"gart","kind":"target","name":"GART (trifunctional purine synthesis enzyme)","route":"/targets/gart/"}],"cancer":[{"id":"glioblastoma","kind":"cancer","name":"Glioma & glioblastoma","route":"/cancers/glioblastoma/"},{"id":"sclc","kind":"cancer","name":"Small-cell lung cancer","route":"/cancers/sclc/"}],"term":[{"id":"gvhd","kind":"term","name":"Graft-versus-host disease (GVHD) and graft-versus-leukaemia","route":"/terms/gvhd/"}]}}