ATP-dependent RNA helicase DDX42 (DEAD box protein 42, splicing factor 3B-associated 125 kD protein, SF3b125, RNA helicase-related protein, RNAHP, RNA helicase-like protein, SF3b DEAD-box protein, RHELP, DDX42)

Function

• ATP-dependent RNA helicase
• binds to partially double-stranded RNAs (dsRNAs) in order to unwind RNA secondary structures
• unwinding is promoted in the presence of single-strand RNA binding proteins
• mediates RNA duplex formation thereby displacing the single-strand RNA binding protein
• ATP & ADP modulate its activity
  • ATP binding & hydrolysis by DDX42 triggers RNA strand separation
  • ADP-bound form triggers annealing of complementary RNA strands
• component of splicing factor SF3B

Structure

• belongs to the DEAD box helicase family, DDX42 subfamily
• cntains 1 helicase ATP-binding domain
• contains 1 helicase C-terminal domain

Compartment

• nuclear speckle, nucleus, Cajal body
• isoform 2 is present in Cajal bodies & nuclear speckles

Alternative splicing

named isoforms=2

Expression

• expressed in several cell lines (at protein level)
• expressed in liver, lung, tonsil, thymus, muscle & pancreatic islets

More general terms

• DEAD box ATP-dependent helicase
• RNA-binding protein
• phosphoprotein

Component of

• splicing factor 3B (SF3B)

Database

• UniProt: http://www.uniprot.org/uniprot/Q86XP3.html