UTP14A

UTP14A is a ribosome biogenesis factor of the small subunit (SSU) processome that couples assembly status of the maturing pre-ribosome to the activation of the DEAH-box helicase that triggers pre-40S release [PMID:26729466, PMID:bio_10.1101_2025.09.29.679232]. It directly binds the helicase Dhr1/DHX37 through a conserved sequence motif, stimulating its RNA unwinding and ATPase activities and enhancing its RNA binding; this interaction, together with Bud23, is required for stable recruitment of the helicase to the pre-ribosome so that it can unwind U3 snoRNA and initiate nucleolar pre-40S release (PMID:26729466, PMID:30910870). UTP14A crosslinks to pre-rRNA within the SSU processome and is additionally required for efficient recruitment of the RNA exosome, positioning it as a sensor that communicates compositional maturation state to both the exosome and the helicase [PMID:29925570, PMID:bio_10.1101_2025.09.29.679232]. Beyond ribosome assembly, human UTP14A has been implicated in oncogenic protein homeostasis: it forms a complex with USP36 and Fbw7γ to inhibit Fbw7γ-mediated ubiquitination of c-Myc, enriching c-Myc in the nucleolus within a c-Myc/UTP14A positive feedback loop (PMID:30343112), and it acts downstream of P16INK4A as an E3 ligase activity that ubiquitinates RB1 at K810 to drive its degradation (PMID:39351198). It also promotes angiogenesis by upregulating PDGFA transcription and secretion (PMID:30929921).

1. 2016 High

   Established that Utp14 is not merely a structural processome component but a direct activator of the Dhr1 helicase, defining the mechanistic link between Utp14 and U3 snoRNA removal during pre-40S maturation.

   Evidence In vitro unwinding assay, yeast two-hybrid, co-IP and site-directed mutagenesis with genetic epistasis in yeast

   PMID:26729466

   Open questions at the time

   • Did not provide an atomic structure of the Utp14-Dhr1 interface
   • Human ortholog activity not yet tested in this study
2. 2018 Medium

   Positioned Utp14 physically on the pre-rRNA and revealed a second output of its function—recruitment of the RNA exosome—implying it integrates assembly signals for both exosome and helicase.

   Evidence CRAC pre-rRNA crosslinking, yeast two-hybrid and quantitative proteomics of SSU particles

   PMID:29925570

   Open questions at the time

   • Mechanism by which Utp14 senses assembly status not resolved
   • Direct vs. indirect exosome recruitment not distinguished
3. 2018 Medium

   Identified a non-ribosomal role for human UTP14A in stabilizing the oncoprotein c-Myc, connecting a ribosome biogenesis factor to deubiquitination machinery and tumor-relevant signaling.

   Evidence MS complex identification, reciprocal co-IP, ubiquitination assay, shRNA xenograft and localization analysis

   PMID:30343112

   Open questions at the time

   • Single lab without independent replication
   • Whether c-Myc stabilization depends on UTP14A's processome function is unclear
4. 2019 High

   Resolved the structural basis of helicase activation, showing the human UTP14A motif stimulates DHX37 ATPase via its unique C-terminal domain and defining the helicase translocation mechanism.

   Evidence Crystal structure of DHX37 with ssRNA, in vitro ATPase and RNA-binding assays, mutagenesis and in vivo complementation

   PMID:30910870

   Open questions at the time

   • No co-structure of the UTP14A-DHX37 complex
   • Conformational ATP-dependent translocation inferred rather than directly observed
5. 2019 Medium

   Extended UTP14A oncogenic function to angiogenesis by linking it to PDGFA-driven paracrine signaling in colorectal cancer.

   Evidence RNA-seq, shRNA knockdown, conditioned-medium HUVEC tube formation/migration with rescue and imatinib block, in vivo Matrigel plug

   PMID:30929921

   Open questions at the time

   • Mechanism of PDGFA transcriptional upregulation not defined
   • Single lab
6. 2021 Low

   Associated UTP14A with PERK/eIF2α/GRP78 ER stress signaling in esophageal squamous cell carcinoma, but only at the level of phenotype and pathway readout.

   Evidence shRNA knockdown, overexpression, proliferation/migration assays, xenograft and western blot pathway readout

   PMID:33391409

   Open questions at the time

   • No direct biochemical interaction demonstrated between UTP14A and PERK pathway components
   • Causality between UTP14A and ER stress activation not established
7. 2024 Medium

   Defined an E3 ligase output for UTP14A acting downstream of P16INK4A, identifying RB1 K810 as a ubiquitination site whose modification drives RB1 degradation.

   Evidence Ubiquitination assay with K810 site mutant, P16INK4A/UTP14A loss- and gain-of-function, proteome-scale ubiquitination analysis

   PMID:39351198

   Open questions at the time

   • Direct E3 ligase catalytic activity of UTP14A not reconstituted with purified components
   • Single lab
8. 2025 Medium

   Captured the dynamic trajectory by which Utp14 probes maturing processome surfaces to ultimately position and activate Dhr1, and showed exosome tethering is redundant, unifying the helicase- and exosome-coupling roles into one assembly-checkpoint model.

   Evidence Cryo-EM of 16 native SSU processome intermediates with genetic data (preprint)

   PMID:bio_10.1101_2025.09.29.679232

   Open questions at the time

   • Preprint not yet peer-reviewed
   • Molecular signal communicated from exosome to Dhr1 via Utp14 not defined at residue level

• How UTP14A's nucleolar ribosome biogenesis function mechanistically relates to its reported E3 ligase and c-Myc-stabilizing activities in cancer remains unresolved.
• No structural or biochemical reconciliation of processome vs. ubiquitin-pathway functions
• Whether E3 ligase activity is intrinsic or complex-dependent is unknown