The role of ABCE1 in eukaryotic posttermination ribosomal recycling.
After termination, eukaryotic 80S ribosomes remain associated with mRNA, P-site deacylated tRNA, and release factor eRF1 and must be recycled by dissociating these ligands and separating ribosomes into subunits. Although recycling of eukaryotic posttermination complexes (post-TCs) can be mediated by initiation factors eIF3, eIF1, and eIF1A (Pisarev et al., 2007), this energy-free mechanism can function only in a narrow range of low Mg(2+) concentrations. Here, we report that ABCE1, a conserved and essential member of the ATP-binding cassette (ABC) family of proteins, promotes eukaryotic ribosomal recycling over a wide range of Mg(2+) concentrations. ABCE1 dissociates post-TCs into free 60S subunits and mRNA- and tRNA-bound 40S subunits. It can hydrolyze ATP, GTP, UTP, and CTP. NTP hydrolysis by ABCE1 is stimulated by post-TCs and is required for its recycling activity. Importantly, ABCE1 dissociates only post-TCs obtained with eRF1/eRF3 (or eRF1 alone), but not post-TCs obtained with puromycin in eRF1's absence.
Pisarev
Andrey V
AV
Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
Skabkin
Maxim A
MA
Pisareva
Vera P
VP
Skabkina
Olga V
OV
Rakotondrafara
Aurélie M
AM
Hentze
Matthias W
MW
Hellen
Christopher U T
CU
Pestova
Tatyana V
TV
D018528:ATP-Binding Cassette Transporters / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D003570:Cytidine Triphosphate / Q000378:metabolism; D039642:Eukaryotic Initiation Factors / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D008274:Magnesium / Q000378:metabolism; D010454:Peptide Termination Factors / Q000378:metabolism; D014176:Protein Biosynthesis; D054657:Ribosome Subunits / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D014544:Uridine Triphosphate / Q000378:metabolism
C501917:ABCE1 protein, human; D018528:ATP-Binding Cassette Transporters; C489002:ETF1 protein, human; D039642:Eukaryotic Initiation Factors; D010454:Peptide Termination Factors; D003570:Cytidine Triphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D008274:Magnesium; D014544:Uridine Triphosphate