scavenger mRNA-decapping enzyme DcpS; m7GpppX diphosphatase; DCS-1; Hint-related 7meGMP-directed hydrolase; histidine triad protein member 5; HINT-5 (DCPS, DCS1, HINT5, HSPC015)

Function

• degradation of mRNAs
  • normal mRNA turnover
  • nonsense-mediated mRNA decay
  • decapping scavenger enzyme that catalyzes cleavage of a residual cap structure following degradation of mRNAs by 3'->5' exosome-mediated mRNA decay pathway
• removes the 7-methyl guanine cap structure from mRNA fragments shorter than 10 nucleotides produced by 3'->5' exosome-mediated mRNA decay
• specifically releases 5'-phosphorylated RNA fragments & m7GMP
• degrades m7GDP to m7GMP
• does not hydrolyze unmethylated cap analog (GpppG)
• no activity towards mRNA > 25 nucleotides
• may play a role in the 5'->3 mRNA decay pathway
• role in first intron splicing of pre-mRNAs
• associates with exosome multienzyme ribonuclease complex, EXOSC3 & EXOSC4

Structure

• homodimer
• belongs to the HIT family
• C-terminal histidine triad (HIT) motif & the N-terminal domain are required for the decapping activity
• N-terminus is necessary, but not sufficient, for binding cap structures

Compartment

• nucleus, cytoplasm
• predominantly located in nucleus
• nucleocytoplasmic shuttling is XPO1/CRM1-dependent

Expression

• detected in liver, brain, kidney, testis & prostate
• up-regulated by menadione
• up-regulated by the transcription factor LTF isoform delta-lactoferrin (at protein level)

Pathology

• defects in DCPS are the cause of Al-Raqad syndrome

More general terms

• mRNA decapping enzyme
• human longevity protein

Component of

• mRNA decay complex

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=28960
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:28960
• OMIM: https://mirror.omim.org/entry/610534
• OMIM: https://mirror.omim.org/entry/616459
• UniProt: http://www.uniprot.org/uniprot/Q96C86.html