inosine-5'-monophosphate dehydrogenase 1; IMP dehydrogenase 1; IMPD 1; IMPDH 1; IMPDH-I (IMPDH1, IMPD1)

Function

• rate limiting enzyme in the de novo synthesis of guanine nucleotides, thus role in regulation of cell growth
• may also have a role in the development of malignancy & the growth progression of some tumors
• purine metabolism; XMP biosynthesis via de novo pathway
• XMP from IMP: step 1/1

Cofactor: K+ (putative)

inosine 5'-phosphate + NAD+ + H2O = xanthosine 5'-phosphate + NADH

Structure

• homotetramer
• belongs to the IMPDH/GMPR family
• contains 2 CBS domains

Alternative splicing

named isoforms=3

Expression

• IMP type 1 predominates in normal leukocytes
• IMP type 2 predominates over type 1 in tumors

Pathology

• defects in IMPDH1 are the cause of retinitis pigmentosa type 10

More general terms

• inosine 5' monophosphate [IMP] dehydrogenase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3614
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3614
• OMIM: https://mirror.omim.org/entry/146690
• OMIM: https://mirror.omim.org/entry/180105
• UniProt: http://www.uniprot.org/uniprot/P20839.html