Reaction: SUPV3L1:PNPT1 hydrolyzes mitochondrial RNA to yield 4-5 nucleotide oligoribonucleotides
- in pathway: Mitochondrial RNA degradation
A dimer of SUPV3L1 (SUV3, hSUV3) and three molecules of PNPT1 (PNPase) form a complex, the degradosome, that is localized with RNA adjacent to nucleoids (Borowski et al. 2013) and that unwinds double-stranded RNA (Jain et al. 2022) and exonucleolytically degrades the resulting single-stranded RNA (Wang et al. 2009, Szczesny et al. 2010, Borowski et al. 2013). PNPT1 is a 3'-5' exonuclease that produces 4-5 nucleotide RNAs called nanoRNAs (Lin et al. 2012, Szewczyk et al. 2020) which are then degraded by the REXO2 dimer (Szewczyk et al. 2020).
GRSF1 binds regions of particular RNAs that contain quadruplex G structures, interacts with SUPV3L1:PNPT1 via the RNA, and unwinds the quadruplex G to yield a single-stranded RNA that is a substrate for SUPV3L1:PNPT1 (Pietras et al. 2018). Silencing of PNPT1 (Silva et al. 2018) or a mutation that prematurely truncates the C-terminus of SUPV3L1 (van Esveld et al. 2022) causes accumulation of double-stranded RNA in mitochondria.
GRSF1 binds regions of particular RNAs that contain quadruplex G structures, interacts with SUPV3L1:PNPT1 via the RNA, and unwinds the quadruplex G to yield a single-stranded RNA that is a substrate for SUPV3L1:PNPT1 (Pietras et al. 2018). Silencing of PNPT1 (Silva et al. 2018) or a mutation that prematurely truncates the C-terminus of SUPV3L1 (van Esveld et al. 2022) causes accumulation of double-stranded RNA in mitochondria.
Reaction - small molecule participants:
H2O [mitochondrial matrix]
Reactome.org reaction link: R-HSA-9836585
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Reaction input - small molecules:
water
Reaction output - small molecules:
Reactome.org link: R-HSA-9836585