ANKZF1 is a cytosolic tRNA endonuclease in the ribosome-associated quality-control pathway. It acts after stalled-ribosome splitting on 60S ribosome-nascent-chain complexes, cleaving the terminal 3'-CCA region of P-site peptidyl-tRNA to release incomplete nascent polypeptides for degradation and to generate tRNA repair intermediates that can be recycled. ANKZF1 also binds VCP/p97 and has a stress-responsive mitochondrial context, translocating to mitochondria under oxidative stress and supporting mitochondrial integrity.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0036503 ERAD pathway | IBA GO_REF:0000033 | REMOVE | Summary: Remove. The phylogenetic transfer appears to over-project a Vms1/Cdc48 quality-control relationship into ERAD. Human ANKZF1 evidence supports cytosolic ribosome-associated quality control and oxidative-stress mitochondrial context, not direct endoplasmic-reticulum-associated degradation. Reason: The experimentally supported conserved function is cleavage of peptidyl-tRNA on 60S RQC complexes, with downstream nascent-chain degradation. That is distinct from the ERAD pathway. Supporting Evidence: PMID:30244831 ANKZF1 does not function as a peptidyl-tRNA hydrolase. PMID:31011209 ANKZF1 and Vms1p sever |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: Correct broad localization. UniProt and the oxidative-stress study place ANKZF1 in the cytoplasm, with stress-dependent mitochondrial translocation. Reason: Cytoplasm is a valid broad cellular component for ANKZF1, although the core RQC activity is more specifically cytosolic. Supporting Evidence: PMID:28302725 ANKZF1 is located diffusely in the cytoplasm |
| GO:0005515 protein binding | IPI PMID:22190034 Global landscape of HIV-human protein complexes. | MARK AS OVER ANNOTATED | Summary: Over-annotated. The source is a large-scale HIV-host interaction study and the generic protein binding term does not describe ANKZF1's biochemical role. Reason: Generic protein binding is uninformative for ANKZF1. A biologically relevant interaction is VCP/p97 binding through the VIM motif (consensus RX5AAX2R, defined in Stapf et al. 2011, which identified ANKZF1/ZNF744 as a VIM-containing p97 cofactor), but this HIV AP-MS annotation should not be treated as core function. Supporting Evidence: PMID:22190034 physical interactions of all 18 HIV-1 proteins and polyproteins with host |
| GO:0072344 rescue of stalled cytosolic ribosome | TAS Reactome:R-HSA-9948299 | ACCEPT | Summary: Correct. Reactome places ANKZF1 in the RQC pathway, where it cleaves the tRNA portion of peptidyl-tRNA on stalled-ribosome 60S complexes. Reason: Rescue of stalled cytosolic ribosomes is a core biological process for ANKZF1 because its tRNA cleavage releases nascent chains from 60S RQC complexes. Supporting Evidence: Reactome:R-HSA-9948299 ANKZF1, which interacts with VCP, cleaves the C-terminal |
| GO:0004521 RNA endonuclease activity | TAS Reactome:R-HSA-9948427 | MODIFY | Summary: The activity is correct but the more specific term tRNA-specific ribonuclease activity better captures ANKZF1's substrate and reaction. Reason: Reactome describes cleavage of the tRNA portion of peptidyl-tRNA. Use the more specific tRNA-specific ribonuclease activity term rather than generic RNA endonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: Reactome:R-HSA-9948427 ANKZF1 cleaves the C-terminal 3 nucleotides, CCA, of the tRNA |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9948427 | ACCEPT | Summary: Correct. The RQC substrate and Reactome event are cytosolic ribosome-nascent-chain complexes. Reason: Cytosol is the best core cellular component for the RQC tRNA endonuclease activity. Supporting Evidence: PMID:32075755 Ribosome-associated quality control (RQC) disassembles aberrantly stalled |
| GO:0004521 RNA endonuclease activity | IDA PMID:30244831 Release of Ubiquitinated and Non-ubiquitinated Nascent Chain... | MODIFY | Summary: The experimental activity is correct but should be represented by the more specific tRNA-specific ribonuclease activity term. Reason: Kuroha et al. showed that ANKZF1 induces specific cleavage in the acceptor arm of 60S-bound P-site tRNA, so a tRNA-specific ribonuclease term is more informative than generic RNA endonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: PMID:30244831 specific cleavage in the acceptor arm of 60S-bound P site tRNA |
| GO:0004521 RNA endonuclease activity | IDA PMID:31011209 Mechanism for recycling tRNAs on stalled ribosomes. | MODIFY | Summary: The experimental activity is correct but should be represented by the more specific tRNA-specific ribonuclease activity term. Reason: The paper identifies precise cleavage of the terminal 3'CCA nucleotides of polypeptidyl-tRNAs on RQC complexes, matching tRNA-specific ribonuclease activity more closely than generic RNA endonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: PMID:31011209 polypeptidyl-tRNAs on RQC complexes by precisely cleaving off the terminal 3'CCA |
| GO:0006515 protein quality control for misfolded or incompletely synthesized proteins | IDA PMID:29632312 Vms1 and ANKZF1 peptidyl-tRNA hydrolases release nascent cha... | ACCEPT | Summary: Correct. ANKZF1 acts in ribosome-associated quality control to release nascent chains from stalled ribosomes for degradation. Reason: This term captures the protein-quality-control outcome of ANKZF1's RQC activity. Supporting Evidence: PMID:29632312 Failure to degrade the NCs leads to protein aggregation and proteotoxic stress |
| GO:0006515 protein quality control for misfolded or incompletely synthesized proteins | IDA PMID:30244831 Release of Ubiquitinated and Non-ubiquitinated Nascent Chain... | ACCEPT | Summary: Correct. The mammalian RQC reconstitution links ANKZF1-mediated tRNA cleavage to release of nascent chains that can be degraded by the proteasome. Reason: ANKZF1 directly supports quality control of aberrant translation products in RQC. Supporting Evidence: PMID:30244831 In conclusion, ANKZF1 induces specific tRNA cleavage in ubiquitinated 60S RNCs |
| GO:0006515 protein quality control for misfolded or incompletely synthesized proteins | IDA PMID:31011209 Mechanism for recycling tRNAs on stalled ribosomes. | ACCEPT | Summary: Correct. Cleavage of polypeptidyl-tRNAs on RQC complexes releases ubiquitinated nascent proteins for proteasomal degradation. Reason: The activity is a core protein quality-control step for incompletely synthesized polypeptides on stalled ribosomes. Supporting Evidence: PMID:31011209 releases ubiquitinated nascent proteins from 60S ribosomal subunits for proteasomal |
| GO:0006515 protein quality control for misfolded or incompletely synthesized proteins | IDA PMID:32075755 ELAC1 Repairs tRNAs Cleaved during Ribosome-Associated Quali... | ACCEPT | Summary: Correct. ELAC1 repair work confirms ANKZF1-dependent tRNA cleavage during ribosome stalling in mammalian cells. Reason: The paper supports ANKZF1 as a cellular RQC factor whose cleavage products are repaired and recycled after stalled-ribosome events. Supporting Evidence: PMID:32075755 Deleting ELAC1 leads to the ANKZF1-dependent accumulation of unrepaired tRNA intermediates |
| GO:0072344 rescue of stalled cytosolic ribosome | IDA PMID:29632312 Vms1 and ANKZF1 peptidyl-tRNA hydrolases release nascent cha... | ACCEPT | Summary: Correct. Purified human ANKZF1 can act on stalled-ribosome peptidyl-tRNA substrates in the conserved RQC release step. Reason: The annotation captures the RQC/ribosome-rescue context of the ANKZF1 activity. Supporting Evidence: PMID:29632312 Purified Ankzf1 |
| GO:0072344 rescue of stalled cytosolic ribosome | IDA PMID:30244831 Release of Ubiquitinated and Non-ubiquitinated Nascent Chain... | ACCEPT | Summary: Correct. In vitro mammalian RQC reconstitution shows ANKZF1 acting on 60S-bound P-site tRNA after stalled-ribosome processing. Reason: ANKZF1-mediated cleavage of 60S RQC complexes is a direct stalled-ribosome rescue step. Supporting Evidence: PMID:30244831 Here, we reconstituted the mammalian RQC pathway in vitro |
| GO:0072344 rescue of stalled cytosolic ribosome | IDA PMID:31011209 Mechanism for recycling tRNAs on stalled ribosomes. | ACCEPT | Summary: Correct. ANKZF1 liberates peptidyl-tRNAs from stalled ribosomes by cleaving the terminal 3'CCA region. Reason: This is a direct mechanistic description of the stalled-ribosome rescue role. Supporting Evidence: PMID:31011209 ANKZF1 liberates peptidyl-tRNAs |
| GO:0072344 rescue of stalled cytosolic ribosome | IDA PMID:32075755 ELAC1 Repairs tRNAs Cleaved during Ribosome-Associated Quali... | ACCEPT | Summary: Correct. The ELAC1 study describes ANKZF1 cleavage of P-site tRNA as a key RQC step after ribosome stalling. Reason: The annotation is directly supported by stalled-ribosome RQC evidence. Supporting Evidence: PMID:32075755 RQC is the cleavage of P-site tRNA by the endonuclease ANKZF1 |
| GO:0140101 catalytic activity, acting on a tRNA | IDA PMID:30244831 Release of Ubiquitinated and Non-ubiquitinated Nascent Chain... | MODIFY | Summary: Correct substrate class but too broad. ANKZF1's activity is specifically tRNA ribonuclease cleavage in the 60S RQC substrate context. Reason: Replace the generic tRNA catalytic-activity term with tRNA-specific ribonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: PMID:30244831 ANKZF1 induces specific tRNA cleavage in ubiquitinated 60S RNCs |
| GO:0140101 catalytic activity, acting on a tRNA | IDA PMID:31011209 Mechanism for recycling tRNAs on stalled ribosomes. | MODIFY | Summary: Correct substrate class but too broad. The paper supports precise tRNA cleavage rather than an unspecified tRNA catalytic activity. Reason: Replace the generic tRNA catalytic-activity term with tRNA-specific ribonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: PMID:31011209 terminal 3'CCA nucleotides universal to all tRNAs |
| GO:0140101 catalytic activity, acting on a tRNA | IDA PMID:32075755 ELAC1 Repairs tRNAs Cleaved during Ribosome-Associated Quali... | MODIFY | Summary: Correct substrate class but too broad. ANKZF1 is a tRNA endonuclease in RQC, not merely a generic enzyme acting on tRNA. Reason: Replace the generic tRNA catalytic-activity term with tRNA-specific ribonuclease activity. Proposed replacements: tRNA-specific ribonuclease activity Supporting Evidence: PMID:32075755 tRNAs cleaved by ANKZF1 for CCA re-addition |
| GO:0005737 cytoplasm | IDA PMID:28302725 Ankyrin repeat and zinc-finger domain-containing 1 mutations... | ACCEPT | Summary: Correct. The disease/stress paper reports diffuse cytoplasmic localization with translocation to mitochondria under cellular stress. Reason: Cytoplasm is experimentally supported, though the main RQC activity is cytosolic. Supporting Evidence: PMID:28302725 ANKZF1 is located diffusely in the cytoplasm |
| GO:0070301 cellular response to hydrogen peroxide | IMP PMID:28302725 Ankyrin repeat and zinc-finger domain-containing 1 mutations... | KEEP AS NON CORE | Summary: Supported but non-core. ANKZF1 translocates to mitochondria during oxidative stress and loss of ANKZF1 affects mitochondrial integrity and respiration under stress. Reason: Hydrogen-peroxide response is an experimentally observed stress phenotype and localization context, but the best-supported core molecular function is RQC-associated tRNA endonuclease activity. Supporting Evidence: PMID:28302725 translocates to the mitochondria upon cellular stress |
| GO:0016020 membrane | HDA PMID:19946888 Defining the membrane proteome of NK cells. | MARK AS OVER ANNOTATED | Summary: Over-annotated. The source is a high-throughput NK-cell membrane proteome and does not establish ANKZF1 as a membrane protein. Reason: UniProt and direct ANKZF1 studies support cytoplasmic/cytosolic localization with stress-dependent mitochondrial translocation, not stable membrane residence. Supporting Evidence: PMID:19946888 transiently associated with membranes |
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Download this section (compressed HTML)Q: Does human ANKZF1 directly drive catabolism of mitochondrial proteins, or is the mitochondrial connection limited to stress-dependent localization and mitochondrial integrity phenotypes downstream of its RQC/VCP biology?
Suggested experts: Siu Sylvia Lee, Shin-ichi Kuroha, Sichen Shao
Q: In mammalian cells, does ANKZF1 act on mitochondria-targeted stalled nascent chains through the same cytosolic RQC substrate state, or through a distinct organelle-proximal mechanism?
Suggested experts: Siu Sylvia Lee, Sichen Shao
Q: Is the VCP/p97 interaction via the ANKZF1 VIM motif (consensus RX5AAX2R) required for ANKZF1's RQC nascent-chain release activity in cells, and should ANKZF1 carry a specific VCP/p97-binding molecular-function annotation rather than only generic protein binding?
Suggested experts: Alexander Buchberger, Sichen Shao
Q: Does ANKZF1-mediated RQC limit toxic repeat-associated non-AUG (RAN) translation products in neurons through its canonical tRNA-cleavage/nascent-chain release activity, and is this dependent on catalytic activity rather than a scaffolding role?
Suggested experts: Peter K Todd, Sami J Barmada
Experiment: In endogenous ANKZF1 knockout cells rescued with wild-type, catalytic-dead, and VIM-mutant ANKZF1, compare turnover of defined mitochondrial protein quality-control substrates with turnover of stalled cytosolic RQC reporters after oxidative stress and translation-stall induction.
Hypothesis: ANKZF1's mitochondrial stress phenotype is separable from direct mitochondrial protein catabolism.
Type: genetic rescue and quantitative protein-turnover assay
Experiment: Use reporters encoding mitochondrial-targeting sequences followed by defined ribosome-stalling motifs, then assay ANKZF1-dependent tRNA cleavage intermediates, nascent-chain ubiquitination, VCP dependence, and subcellular localization of the stalled complexes.
Hypothesis: ANKZF1 acts on mitochondria-targeted translation products only after they enter the canonical cytosolic RQC substrate state.
Type: stalled-translation reporter assay
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