high affinity cAMP-specific 3',5'-cyclic phosphodiesterase 7A; HCP1; TM22 (PDE7A)

Function

• hydrolyzes the second messenger cAMP
• may have a role in muscle signal transduction
• purine metabolism; 3',5'-cyclic AMP degradation; AMP from 3',5'-cyclic AMP: step 1/1
• interacts with CBFA2T3

adenosine 3',5'-cyclic phosphate + H2O = adenosine 5'-phosphate

Cofactor:

• binds 2 divalent metal cations per subunit
• site 1 may preferentially bind Zn+2
• site 2 has a preference for Mg+2 &/or Mn+2

Inhibition:

• insensitive to all selective PDE inhibitors

Structure

• composed of a C-terminal catalytic domain containing two putative divalent metal sites & an N-terminal regulatory domain
• belongs to the cyclic nucleotide phosphodiesterase family, PDE7 subfamily

Compartment

• isoform PDE7A1 (57 kDa)
  • cytoplasm, cytosol
  • located mostly to soluble cellular fractions
• isoform PDE7A2 (50 kDa)
  • cytoplasm
  • located in particulate cellular fractions

Alternative splicing

named isoforms=3; PDE7A1, PDE7A2, PDE7A3

Expression

• PDE7A1
  • high expression in skeletal muscle
  • low expression in brain & heart
  • expressed as well in two T-cell lines
• PDE7A2
  • high expression in skeletal muscle
  • low expression in heart
• developmentally regulated
• PDE7A1 & PDE7A2 are found in several fetal tissues
• expression is reduced throughout development
• persists strongly only in adult skeletal muscle

More general terms

• phosphodiesterase 7

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5150
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5150
• OMIM: https://mirror.omim.org/entry/171885
• UniProt: http://www.uniprot.org/uniprot/Q13946.html