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Showing TENT2 — GLD2 is a alias.

TENT2

Poly(A) RNA polymerase GLD2 · UniProt Q6PIY7

Length
484 aa
Mass
56.0 kDa
Annotated
2026-06-10
27 papers in source corpus 14 papers cited in narrative 16 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

TENT2 (GLD-2/PAPD4/TUT2) is a cytoplasmic non-canonical poly(A) polymerase and terminal nucleotidyltransferase that controls post-transcriptional gene expression by extending or tailing the 3' ends of distinct RNA classes (PMID:15070731, PMID:27284165). As a poly(A) polymerase it adds adenosines to specific mRNAs and stimulates their translation, and recruitment to an RNA target is sufficient to trigger this activity (PMID:15070731). Biochemically it is a bona fide adenylyltransferase with an ~83-fold preference for ATP over UTP, but in isolation the apo-enzyme adds only single nucleotides; processive polyadenylation requires accessory RNA-binding proteins, and a single active-site histidine insertion is sufficient to switch its specificity from ATP to UTP (PMID:27284165). Substrate selection and recruitment are governed by interacting RNA-binding proteins: CPEB/CPEB1 directs cytoplasmic polyadenylation, including dendritic, plasticity-linked translation in hippocampal neurons (PMID:15987818, PMID:27495319), while the STAR-family protein QKI-7 engages TENT2 through a short N-terminal peptide and bridges it to Argonaute 2-associated miR-122, relieving N-terminal autoinhibition and promoting target-specific 3' adenylation (PMID:26926106, PMID:31792053, PMID:34288801). Beyond mRNA, TENT2 monoadenylates specific miRNAs and broader small non-coding RNAs, a modification that can stabilize the RNA and shape its biogenesis (PMID:23200856, PMID:36071058). Its activity is further tuned by site-specific phosphorylation of its disordered N-terminal domain, with PKA- and Akt1-mediated phosphorylation of S116 abolishing nucleotide-addition activity and QKI-7 binding able to override this deactivation (PMID:31057087, PMID:34288801). In vivo, hippocampal TENT2 supports long-term potentiation and, through miRNA monoadenylation rather than bulk mRNA poly(A) tail changes, regulates neuronal excitability and excitatory/inhibitory balance (PMID:27495319, PMID:40101932).

Mechanistic history

Synthesis pass · year-by-year structured walk · 16 steps
  1. 2004 High

    Established that mammalian GLD-2 homologs are cytoplasmic poly(A) polymerases whose activity is gated by recruitment to RNA rather than being constitutive, defining the core enzymatic identity of the gene.

    Evidence Tethered-function assay in Xenopus oocytes plus in vitro poly(A) polymerase assay

    PMID:15070731

    Open questions at the time
    • Did not identify endogenous recruiting partners
    • No structural basis for the activity
  2. 2005 High

    Connected TENT2 to the cytoplasmic polyadenylation machinery and to the nervous system by showing a conserved physical interaction with CPEB and brain expression in plasticity-associated regions.

    Evidence In vitro PAP assay, Co-IP with CPEB, in situ hybridization and immunohistochemistry

    PMID:15987818

    Open questions at the time
    • Did not demonstrate CPEB-dependent translation of specific endogenous mRNAs
    • No functional neuronal phenotype shown
  3. 2012 High

    Extended TENT2 substrates beyond mRNA by showing it monoadenylates specific miRNAs and that this 3' modification stabilizes them, broadening its role to small-RNA metabolism.

    Evidence Loss-of-function in human fibroblasts, Northern blot, in vitro adenylation and miRNA stability assays

    PMID:23200856

    Open questions at the time
    • Did not define what targets miRNA subsets for monoadenylation
    • Recruiting factors for miRNA tailing unknown
  4. 2016 High

    Defined the intrinsic enzymology of human TENT2 — an ATP-preferring adenylyltransferase that is distributive alone and requires partner proteins for processivity — establishing why accessory factors are mechanistically essential.

    Evidence In vitro reconstitution with purified recombinant enzyme, nucleotide preference assays, active-site mutagenesis

    PMID:27284165

    Open questions at the time
    • Did not identify all processivity-conferring partners
    • Physiological substrate spectrum not mapped
  5. 2016 High

    Identified QKI-7 as a sequence-specific recruiter that brings TENT2 to defined mRNAs (hnRNPA1, p27kip1, β-catenin) and linked this polyadenylation to anti-mitogenic signaling, showing how target specificity is achieved in somatic cells.

    Evidence Co-IP, tethering assays, transcriptional pulse-chase with deadenylase suppression, reporter assays

    PMID:26926106

    Open questions at the time
    • Did not resolve the QKI-7 binding interface on TENT2
    • Signal transduction upstream of recruitment not detailed
  6. 2016 Medium

    Demonstrated a physiological neuronal role: hippocampal TENT2 supports LTP through CPEB1-mediated dendritic polyadenylation, while showing its miRNA monoadenylation did not detectably affect miRNA stability or behavior in KO mice.

    Evidence Hippocampal Gld2 knockout mice, LTP electrophysiology, miRNA monoadenylation and behavioral assays

    PMID:27495319

    Open questions at the time
    • Discrepancy between miRNA tailing and lack of stability/behavior effect unresolved
    • Specific dendritic mRNA targets not enumerated
  7. 2016 High

    Showed TENT2 is a target for viral subversion: HCV core protein directly binds and inhibits it, destabilizing miR-122 by blocking 3'-terminal single-nucleotide tailing, placing TENT2 in host-virus RNA regulation.

    Evidence Co-IP, small RNA sequencing from liver and cell lines, in vitro nucleotidyltransferase and miRNA stability assays

    PMID:27366906

    Open questions at the time
    • Did not map the TENT2 region bound by HCV core
    • In vivo consequences for HCV infection not established
  8. 2019 High

    Revealed phospho-regulation of TENT2 through its disordered N-terminus, with PKA/Akt1 phosphorylation of S116 abolishing activity, linking the enzyme to upstream signaling kinases.

    Evidence Phosphomimetic mutagenesis, in vitro adenylation assays, MS confirmation in HEK293, PKA/Akt1 kinase assays

    PMID:31057087

    Open questions at the time
    • Physiological stimuli that drive S116 phosphorylation not defined
    • Did not show phospho-control of specific RNA targets in cells
  9. 2019 High

    Mechanistically connected recruitment and small-RNA tailing by showing QKI-7 bridges TENT2 to Ago2-bound miR-122 via distinct domains, promoting its 3' adenylation and stabilization.

    Evidence Reciprocal Co-IP (GLD-2/QKI-7, QKI-7/Ago2), in vitro adenylation assay, QKI knockdown/overexpression, Northern blot

    PMID:31792053

    Open questions at the time
    • Generality of Ago2-bridging to other miRNAs untested
    • Structural detail of the ternary complex absent
  10. 2020 High

    Provided the structural basis of mammalian TENT2 activity, showing a positively charged, intrinsically robust polymerase that acts on diverse RNA sequences and resembles TUT7, explaining its substrate promiscuity.

    Evidence X-ray crystallography of rodent GLD-2, in vitro PAP assays with varied RNA substrates, structural comparison

    PMID:32633758

    Open questions at the time
    • No structure of human enzyme bound to a partner protein
    • N-terminal autoinhibitory region not resolved
  11. 2021 Medium

    Integrated the two regulatory layers by showing QKI-7 binding to an N-terminal TENT2 peptide relieves autoinhibition and overrides Akt1-mediated S116 deactivation, while S62 phosphorylation also relieves autoinhibition.

    Evidence In vitro adenylation and peptide-binding assays, phosphomimetic mutagenesis, cellular Akt1 phosphorylation

    PMID:34288801

    Open questions at the time
    • Combinatorial control under physiological signaling untested
    • Did not show override at endogenous targets in cells
  12. 2021 Medium

    Placed TENT2 within a larger cytoplasmic polyadenylation complex by showing DDX6 acts as a positive regulator interacting with Ataxin-2, PABPC1, and PAPD4 to maintain target mRNA poly(A) length and protein output.

    Evidence Ataxin-2 interactome by LC-MS/MS, Co-IP, poly(A) tail length assays, knockdown/overexpression

    PMID:33756349

    Open questions at the time
    • PAPD4 link is indirect through the complex
    • Direct DDX6-TENT2 contact and target mRNA set not defined
  13. 2022 High

    Recontextualized TENT2's role in miRNA metabolism by showing its tailing is selective and includes guanylation/uridylation, but that abolishing adenylation alone has marginal impact while TUT4/7 uridylation, not TENT2, dominates miRNA abundance control.

    Evidence Isogenic TENT2/TUT4/TUT7 KO HEK293T cells, deep sequencing of 3' ends, Northern blot, in vitro tailing, rescue

    PMID:36071058

    Open questions at the time
    • Functional purpose of selective non-adenosine tailing unclear
    • Which miRNAs depend on TENT2 physiologically not pinned down
  14. 2025 High

    Resolved the in vivo neuronal mechanism by showing TENT2 loss eliminates miRNA monoadenylation without altering bulk mRNA poly(A) length, yet increases neuronal excitability and downregulates synaptic transcripts, tying miRNA tailing to excitatory/inhibitory balance.

    Evidence Tent2 KO mouse, direct nanopore poly(A) sequencing, electrophysiology, behavioral and differential-expression analysis

    PMID:40101932

    Open questions at the time
    • Specific monoadenylated miRNAs driving the phenotype not identified
    • Behavioral consequences remain limited
  15. 2025 Medium

    Expanded the substrate repertoire to Pol-III and other small non-coding RNAs, showing TENT2 monoadenylation blocks uridine trimming/extension and, for 7SL RNA, prevents La binding and promotes signal recognition particle assembly.

    Evidence Genome-wide 3' end sequencing of nascent and steady-state sncRNAs in KO cells, functional 7SL RNA analysis (preprint)

    Open questions at the time
    • Preprint, not yet peer-reviewed
    • Recruitment mechanism to Pol-III RNAs unknown
    • Breadth of physiological consequences untested
  16. 2025 Low

    Implicated TENT2 in tRNA-fragment surveillance, showing that without HENMT1-mediated 2'-O methylation, TENT2 (with TUT4) tails 3'-tRFs to promote their degradation.

    Evidence HENMT1 KO system, small RNA sequencing identifying TENT2-dependent tailing (preprint)

    Open questions at the time
    • Preprint; TENT2 role inferred from sequencing rather than direct reconstitution
    • Not independently confirmed
    • Physiological relevance of 3'-tRF tailing unclear

Open questions

Synthesis pass · forward-looking unresolved questions
  • It remains unknown how TENT2 selects among its many RNA substrate classes in a given cell type and what governs the choice between adenylation, guanylation, and uridylation at specific 3' ends.
  • Substrate-partitioning logic across mRNA, miRNA, and sncRNA unknown
  • Physiological signals dictating nucleotide identity undefined

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140098 catalytic activity, acting on RNA 6 GO:0016740 transferase activity 3 GO:0003723 RNA binding 2
Localization
GO:0005829 cytosol 2
Pathway
R-HSA-8953854 Metabolism of RNA 3 R-HSA-112316 Neuronal System 2 R-HSA-74160 Gene expression (Transcription) 2
Partners
AGO2AKT1ATXN2CPEB1DDX6PABPC1PRKACAQKI

Evidence

Reading pass · 16 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2004 Mammalian GLD-2 homologs (human and mouse, later designated TENT2/PAPD4) are cytoplasmic poly(A) polymerases; when tethered to mRNAs in Xenopus oocytes they add poly(A) and stimulate translation, demonstrating that recruitment to RNA is sufficient for polyadenylation activity. Tethered-function assay in Xenopus oocytes (MS2 coat protein tethering), in vitro poly(A) polymerase assay Proceedings of the National Academy of Sciences of the United States of America High 15070731
2005 Vertebrate GLD-2 (TENT2) possesses poly(A) polymerase activity in vivo and in vitro and physically interacts with the cytoplasmic polyadenylation factor CPEB in a conserved manner; it is expressed in the brain in regions associated with synaptic plasticity. In vitro PAP assay, co-immunoprecipitation with CPEB, in situ hybridization and immunohistochemistry RNA (New York, N.Y.) High 15987818
2012 Gld2 (TENT2) directly monoadenylates specific miRNA populations in human fibroblasts and this 3' monoadenylation stabilizes those miRNAs; sensitivity to monoadenylation-induced stability depends on nucleotides in the miRNA 3' end. Biochemical characterization in human fibroblasts, Northern blot, in vitro adenylation assays, miRNA stability measurements after Gld2 depletion Cell reports High 23200856
2016 The STAR-family RNA-binding protein QKI-7 recruits PAPD4 (TENT2) through its unique carboxyl-terminal region to promote cytoplasmic polyadenylation and translational activation of specific target mRNAs (hnRNPA1, p27kip1, β-catenin) in somatic cells; this polyadenylation of p27kip1 is induced by an anti-mitogenic signal. Co-immunoprecipitation, tethering assays, transcriptional pulse-chase analysis with deadenylase suppression, reporter assays, Western blot Nucleic acids research High 26926106
2016 Human Gld2 (TENT2) is a bona fide adenylyltransferase with 83-fold preference for ATP over UTP, displaying promiscuous substrate activity toward miRNA, pre-miRNA, and polyadenylated RNA; apo-Gld2 adds only single nucleotides and processivity requires additional RNA-binding proteins. An active-site histidine insertion converts its specificity from ATP to UTP. In vitro biochemical characterization with purified recombinant enzyme, nucleotide preference assays, active-site mutagenesis, phylogenetic analysis RNA (New York, N.Y.) High 27284165
2016 HCV core protein specifically inhibits GLD-2 (TENT2) by direct interaction in the cytoplasm, leading to destabilization of miR-122 by reducing its 3'-terminal single-nucleotide tailing; GLD-2 can add any single ribonucleotide without adenylate preference to the miR-122 3' end. Co-immunoprecipitation, high-throughput small RNA sequencing from liver biopsies and cell lines, in vitro terminal nucleotidyltransferase assay, miRNA stability assays PLoS pathogens High 27366906
2016 Gld2 (TENT2) interacts with CPEB1 to mediate polyadenylation-induced translation in dendrites of cultured hippocampal neurons; depletion of Gld2 from the hippocampus impairs long-term potentiation evoked by theta burst stimulation. However, miRNA monoadenylation by Gld2 in the hippocampus does not detectably affect miRNA stability or animal behavior in knockout mice. Hippocampal Gld2 knockout mice, electrophysiology (LTP), miRNA monoadenylation measurements, behavioral assays RNA (New York, N.Y.) Medium 27495319
2019 QKI-7 interacts with GLD-2 (TENT2) via its C-terminal region and with Argonaute 2 (Ago2) via its QUA2 domain, thereby recruiting GLD-2 to Ago2-associated miR-122; QKI-7 directly promotes GLD-2-mediated 3' adenylation of miR-122 in vitro and stabilizes miR-122. Co-immunoprecipitation (GLD-2/QKI-7 and QKI-7/Ago2), in vitro adenylation assay, QKI knockdown/overexpression, Northern blot The Journal of biological chemistry High 31792053
2019 Gld2 (TENT2) activity is regulated by site-specific phosphorylation in its disordered N-terminal domain: phosphomimetic substitutions at S62 and S110 increase activity, while phosphomimetic S116 markedly reduces activity. PKA and Akt1 were identified as kinases that phosphorylate Gld2 at S116, abolishing its nucleotide addition activity. Phosphomimetic mutagenesis, in vitro adenylation assays, mass spectrometry confirmation of phosphorylation in HEK293 cells, kinase assays with PKA and Akt1 RNA biology High 31057087
2020 Crystal structures of two rodent GLD-2 (TENT2) proteins revealed that mammalian GLD-2 is an intrinsically robust poly(A) polymerase with an extensively positively charged surface; unlike C. elegans GLD-2 which prefers adenosine-rich RNA substrates, mammalian GLD-2 acts on RNA oligonucleotides of various sequences, and structurally resembles TUT7. X-ray crystallography (crystal structures of rodent GLD-2), in vitro PAP assays with varied RNA substrates, structural comparison Nucleic acids research High 32633758
2021 DDX6 is a positive regulator of PAPD4 (TENT2)-containing cytoplasmic polyadenylation machinery: DDX6 physically interacts with Ataxin-2, PABPC1, and PAPD4; DDX6 downregulation increases proportion of target mRNAs with short poly(A) tails and reduces their protein expression, phenocopying Ataxin-2 downregulation. Ataxin-2 interactome by LC-MS/MS, Co-immunoprecipitation (DDX6/Ataxin-2/PAPD4/PABPC1), poly(A) tail length assays, knockdown/overexpression experiments Biochemical and biophysical research communications Medium 33756349
2021 Gld2 (TENT2) activity and RNA specificity are dynamically regulated by the interplay between phosphorylation and RNA-binding protein interactions: binding of QKI-7 to a short peptide in the Gld2 N-terminal domain relieves autoinhibition and can override Akt1-mediated deactivation at S116; phosphorylation at S62 also relieves N-terminal autoinhibitory function. In vitro adenylation assays, phosphomimetic mutagenesis, binding assays between Gld2 peptides and QKI-7, Akt1 phosphorylation confirmed in cellular context RNA biology Medium 34288801
2022 TENT2 contributes to guanylation and uridylation (not only adenylation) on mature miRNAs; in TENT2 knockout cells, 3' tailing is selective rather than random. Abolishing adenylation alone has marginal impact on miRNA levels, but TUT4/7-mediated uridylation (not TENT2) is the primary regulator of miRNA abundance for most miRNAs. Isogenic TENT2/TUT4/TUT7 single and combination knockout HEK293T cells, deep sequencing of miRNA 3' ends, Northern blot, in vitro tailing assays, rescue experiments Nature communications High 36071058
2025 TENT2 loss in mouse hippocampus eliminates miRNA monoadenylation but has no detectable effect on mRNA total poly(A) tail length (measured by direct nanopore sequencing); Tent2 KO neurons show increased excitability and downregulation of synaptic transmission transcripts, linking TENT2-dependent miRNA tailing to excitatory/inhibitory balance. Tent2 knockout mouse, direct nanopore RNA sequencing (poly(A) tail length), electrophysiology, behavioral assays, differential expression analysis RNA (New York, N.Y.) High 40101932
2025 TENT2 broadly catalyzes monoadenylation of small non-coding RNAs including Pol-III-transcribed RNAs and a subset of snRNAs; TENT2-mediated monoadenylation inhibits post-transcriptional 3' uridine trimming and extension of Pol-III RNAs, and in the case of 7SL RNA prevents La protein association and promotes assembly into cytoplasmic signal recognition particles. Genome-wide 3' end sequencing of nascent and steady-state sncRNAs in TENT2 KO cells, deep sequencing, functional characterization of 7SL RNA biogenesis bioRxivpreprint Medium
2025 In the absence of HENMT1, TENT2 (together with TUT4) tails 3'-tRNA fragments (3'-tRFs), contributing to their degradation; this tailing by TENT2 is revealed when HENMT1-mediated 2'-O methylation is absent. HENMT1 knockout system, small RNA sequencing, identification of TENT2-dependent tailing of 3'-tRFs bioRxivpreprint Low

Source papers

Stage 0 corpus · 27 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2004 Mammalian GLD-2 homologs are poly(A) polymerases. Proceedings of the National Academy of Sciences of the United States of America 118 15070731
2012 Specific miRNA stabilization by Gld2-catalyzed monoadenylation. Cell reports 98 23200856
2005 Vertebrate GLD2 poly(A) polymerases in the germline and the brain. RNA (New York, N.Y.) 88 15987818
2006 The GLD-2 poly(A) polymerase activates gld-1 mRNA in the Caenorhabditis elegans germ line. Proceedings of the National Academy of Sciences of the United States of America 77 17012378
2008 Wispy, the Drosophila homolog of GLD-2, is required during oogenesis and egg activation. Genetics 76 18430932
2009 Two conserved regulatory cytoplasmic poly(A) polymerases, GLD-4 and GLD-2, regulate meiotic progression in C. elegans. Genes & development 65 19339688
2008 GLD2 poly(A) polymerase is required for long-term memory. Proceedings of the National Academy of Sciences of the United States of America 61 18780789
2009 Antagonism between GLD-2 binding partners controls gamete sex. Developmental cell 47 19460348
2022 TENT2, TUT4, and TUT7 selectively regulate miRNA sequence and abundance. Nature communications 44 36071058
2011 The poly(A) polymerase GLD2 is required for spermatogenesis in Drosophila melanogaster. Development (Cambridge, England) 37 21427144
2016 The STAR protein QKI-7 recruits PAPD4 to regulate post-transcriptional polyadenylation of target mRNAs. Nucleic acids research 34 26926106
2014 HBx down-regulated Gld2 plays a critical role in HBV-related dysregulation of miR-122. PloS one 33 24667324
2016 Gld2-catalyzed 3' monoadenylation of miRNAs in the hippocampus has no detectable effect on their stability or on animal behavior. RNA (New York, N.Y.) 31 27495319
2019 The RNA-binding protein QKI-7 recruits the poly(A) polymerase GLD-2 for 3' adenylation and selective stabilization of microRNA-122. The Journal of biological chemistry 26 31792053
2006 Autoregulation of GLD-2 cytoplasmic poly(A) polymerase. RNA (New York, N.Y.) 26 17164476
2016 Nucleotide specificity of the human terminal nucleotidyltransferase Gld2 (TUT2). RNA (New York, N.Y.) 24 27284165
2016 Hepatitis C Virus Core Protein Promotes miR-122 Destabilization by Inhibiting GLD-2. PLoS pathogens 22 27366906
2015 Structural basis for the activation of the C. elegans noncanonical cytoplasmic poly(A)-polymerase GLD-2 by GLD-3. Proceedings of the National Academy of Sciences of the United States of America 22 26124149
2017 Polyadenylation is the key aspect of GLD-2 function in C. elegans. RNA (New York, N.Y.) 19 28490506
2019 Gld2 activity is regulated by phosphorylation in the N-terminal domain. RNA biology 8 31057087
2020 Dose-Dependent Effects of GLD-2 and GLD-1 on Germline Differentiation and Dedifferentiation in the Absence of PUF-8. Frontiers in cell and developmental biology 6 32039211
2004 Tissue-specific modification of gld-2 mRNA in C. elegans: likely C-to-U editing. RNA (New York, N.Y.) 6 15317977
2021 DDX6 is a positive regulator of Ataxin-2/PAPD4 cytoplasmic polyadenylation machinery. Biochemical and biophysical research communications 5 33756349
2021 Gld2 activity and RNA specificity is dynamically regulated by phosphorylation and interaction with QKI-7. RNA biology 4 34288801
2020 Structures of mammalian GLD-2 proteins reveal molecular basis of their functional diversity in mRNA and microRNA processing. Nucleic acids research 2 32633758
2025 Terminal nucleotidyltransferase Tent2 microRNA A-tailing enzyme regulates excitatory/inhibitory balance in the hippocampus. RNA (New York, N.Y.) 1 40101932
2025 Punishment-Induced Suppression of Methamphetamine Self-Administration Is Accompanied by the Activation of the CPEB4/GLD2 Polyadenylation Complex of the Translational Machinery. International journal of molecular sciences 1 40141377

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