ARL8B

UniProt ID: Q9NVJ2
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

ARL8B is a conserved Arf-like small GTPase that associates with lysosomal and endolysosomal membranes in its active GTP-bound state. Through effector interactions with BORC, PLEKHM2/SKIP-kinesin, PLEKHM1/HOPS, VPS41, and RUFY proteins, it coordinates lysosome positioning, endolysosomal cargo delivery, and lysosome fusion or exocytosis in contexts including autophagic cargo degradation, phagosome maturation, antigen presentation, cytolytic granule polarization, plasma membrane repair, and beta-coronavirus egress.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005765 lysosomal membrane
IBA
GO_REF:0000033
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0008089 anterograde axonal transport
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: anterograde axonal transport is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0003924 GTPase activity
IEA
GO_REF:0000002
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTPase activity annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0003925 G protein activity
IEA
GO_REF:0000003
MARK AS OVER ANNOTATED
Summary: ARL8B is a monomeric Arf-like small GTPase, so the heterotrimeric G protein activity term is not the best molecular-function annotation.
Reason: The cited evidence supports small-GTPase biology captured by GO:0003924 GTPase activity, which is already present and accepted; GO:0003925 is over-broad or semantically imprecise for ARL8B.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005525 GTP binding
IEA
GO_REF:0000002
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTP binding annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005765 lysosomal membrane
IEA
GO_REF:0000044
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005819 spindle
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: spindle comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0005829 cytosol
IEA
GO_REF:0000120
MARK AS OVER ANNOTATED
Summary: Cytosol is a generic automated localization and is less informative than ARL8B lysosomal membrane/endolysosomal localization.
Reason: ARL8B cycles between soluble and membrane-associated states, but the curated functional signal is the active lysosomal/endolysosomal membrane pool; generic cytosol is over-annotated for this review.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Small GTPase which cycles between active GTP-bound and inactive GDP-bound states
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes
GO:0015031 protein transport
IEA
GO_REF:0000002
MARK AS OVER ANNOTATED
Summary: The broad protein transport IEA captures the general trafficking theme but is too nonspecific for ARL8B.
Reason: ARL8B evidence supports lysosome positioning and specific late-endosome/phagosome/autophagosome-to-lysosome traffic rather than generic protein transport; the more specific lysosome localization and late endosome-to-lysosome transport annotations are already present and accepted.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:28325809
Arl8b, along with its effectors, orchestrates lysosomal transport and fusion.
IEA
GO_REF:0000120
KEEP AS NON CORE
Summary: axon is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0031901 early endosome membrane
IEA
GO_REF:0000044
ACCEPT
Summary: early endosome membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:36282215
Arl8b determines RUFY1 endosomal localization through regulating its interaction with Rab14.
PMID:36282215
RUFY1 depletion led to a delay in CI-M6PR retrieval from endosomes to the TGN, resulting in impaired delivery of newly synthesized hydrolases to lysosomes.
GO:0031902 late endosome membrane
IEA
GO_REF:0000044
ACCEPT
Summary: late endosome membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0045202 synapse
IEA
GO_REF:0000120
KEEP AS NON CORE
Summary: synapse is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0051233 spindle midzone
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: spindle midzone comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0101004 cytolytic granule membrane
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: cytolytic granule membrane is supported for NK cells, where ARL8B localizes to lytic granules and promotes polarization toward the immune synapse.
Reason: This is a well-supported lysosome-related organelle function in a specialized immune-cell context, not the general core function of ARL8B.
Supporting Evidence:
PMID:24088571
Arl8b colocalizes with perforin, granzyme B, and LAMP-1, markers of lytic granules.
GO:1904115 axon cytoplasm
IEA
GO_REF:0000108
KEEP AS NON CORE
Summary: axon cytoplasm is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005515 protein binding
IPI
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
MARK AS OVER ANNOTATED
Summary: PLEKHM1 binding is real and biologically important for HOPS-linked lysosomal fusion, but generic protein binding is not an informative GO molecular function for ARL8B.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:28325809
Arl8b mediates recruitment of HOPS complex to PLEKHM1-positive vesicle contact sites.
PMID:28325809
Arl8b binding is crucial for PLEKHM1 to promote lysosomal degradation of endocytic and autophagic cargo.
GO:0005515 protein binding
IPI
PMID:32296183
A reference map of the human binary protein interactome.
MARK AS OVER ANNOTATED
Summary: The HuRI protein interaction is a broad interactome finding and does not define a specific ARL8B molecular function beyond generic binding.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:32296183
A reference map of the human binary protein interactome.
GO:0002505 antigen processing and presentation of polysaccharide antigen via MHC class II
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: antigen processing and presentation of polysaccharide antigen via MHC class II is supported by immune-cell lysosomal trafficking studies but is context-specific.
Reason: ARL8B controls delivery of antigen-containing cargo to lysosomal compartments; antigen presentation is a downstream immune-cell outcome rather than the core molecular role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
GO:0005764 lysosome
IEA
GO_REF:0000107
ACCEPT
Summary: lysosome is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0008089 anterograde axonal transport
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: anterograde axonal transport is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0046754 viral exocytosis
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: ARL8B-dependent lysosomal exocytosis is exploited by beta-coronaviruses for viral egress.
Reason: The process annotation is supported for infection biology, but it represents pathogen exploitation of ARL8B-dependent lysosomal exocytosis rather than a core host function.
Supporting Evidence:
PMID:33157038
these viruses use a lysosomal, Arl8b-dependent exocytic pathway for release into the extracellular environment.
GO:1902774 late endosome to lysosome transport
IEA
GO_REF:0000107
ACCEPT
Summary: late endosome to lysosome transport is supported by ARL8B loss-of-function cargo-delivery assays and HOPS recruitment evidence.
Reason: This captures ARL8B-dependent delivery of endocytic cargo to lysosomes, a core part of its endolysosomal trafficking role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
PMID:21802320
Arl8b was found to bind and recruit the VPS41 subunit of the HOPS (homotypic fusion and protein sorting) complex to lysosomes.
PMID:28325809
Arl8b, along with its effectors, orchestrates lysosomal transport and fusion.
GO:0005765 lysosomal membrane
EXP
PMID:16650381
The Arf-family protein, Arl8b, is involved in the spatial di...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005765 lysosomal membrane
EXP
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005765 lysosomal membrane
EXP
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005765 lysosomal membrane
EXP
PMID:29592961
Lysosome-Mediated Plasma Membrane Repair Is Dependent on the...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0031902 late endosome membrane
EXP
PMID:16537643
An N-terminally acetylated Arf-like GTPase is localised to l...
ACCEPT
Summary: late endosome membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0045202 synapse
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: synapse is supported mainly by conserved neuronal ARL8 biology and automated/by-similarity transfer.
Reason: The annotation is plausible for neuronal endolysosomal or presynaptic-vesicle trafficking, but human ARL8B direct evidence in this review is stronger for general lysosome positioning and cargo delivery.
Supporting Evidence:
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005515 protein binding
IPI
PMID:35314674
RUFY3 and RUFY4 are ARL8 effectors that promote coupling of ...
MARK AS OVER ANNOTATED
Summary: RUFY3/RUFY4 interactions support ARL8B-dependent endolysosome motor coupling, but generic protein binding does not capture the specific small-GTPase effector relationship.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:35314674
RUFY3 and RUFY4 are ARL8 effectors that promote coupling of endolysosomes to dynein-dynactin
PMID:35314674
ARL8 can thus regulate both anterograde and retrograde endolysosome transport through interactions with kinesin and dynein-dynactin motors
GO:0003924 GTPase activity
IDA
PMID:16537643
An N-terminally acetylated Arf-like GTPase is localised to l...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTPase activity annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0031901 early endosome membrane
IDA
PMID:36282215
RUFY1 binds Arl8b and mediates endosome-to-TGN CI-M6PR retri...
ACCEPT
Summary: early endosome membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:36282215
Arl8b determines RUFY1 endosomal localization through regulating its interaction with Rab14.
PMID:36282215
RUFY1 depletion led to a delay in CI-M6PR retrieval from endosomes to the TGN, resulting in impaired delivery of newly synthesized hydrolases to lysosomes.
GO:0034498 early endosome to Golgi transport
IDA
PMID:36282215
RUFY1 binds Arl8b and mediates endosome-to-TGN CI-M6PR retri...
KEEP AS NON CORE
Summary: early endosome to Golgi transport is supported by RUFY1-dependent CI-M6PR retrieval work.
Reason: This is a specific cargo-sorting branch of ARL8B biology and supports lysosomal hydrolase delivery, but it is secondary to the major lysosome positioning/fusion role.
Supporting Evidence:
PMID:36282215
RUFY1 depletion led to a delay in CI-M6PR retrieval from endosomes to the TGN, resulting in impaired delivery of newly synthesized hydrolases to lysosomes.
GO:1902946 protein localization to early endosome
IDA
PMID:36282215
RUFY1 binds Arl8b and mediates endosome-to-TGN CI-M6PR retri...
KEEP AS NON CORE
Summary: protein localization to early endosome is supported by RUFY1-dependent CI-M6PR retrieval work.
Reason: This is a specific cargo-sorting branch of ARL8B biology and supports lysosomal hydrolase delivery, but it is secondary to the major lysosome positioning/fusion role.
Supporting Evidence:
PMID:36282215
Arl8b determines RUFY1 endosomal localization through regulating its interaction with Rab14.
GO:0046754 viral exocytosis
IMP
PMID:33157038
Ξ²-Coronaviruses Use Lysosomes for Egress Instead of the Bios...
KEEP AS NON CORE
Summary: ARL8B-dependent lysosomal exocytosis is exploited by beta-coronaviruses for viral egress.
Reason: The process annotation is supported for infection biology, but it represents pathogen exploitation of ARL8B-dependent lysosomal exocytosis rather than a core host function.
Supporting Evidence:
PMID:33157038
these viruses use a lysosomal, Arl8b-dependent exocytic pathway for release into the extracellular environment.
GO:0003925 G protein activity
IDA
PMID:16537643
An N-terminally acetylated Arf-like GTPase is localised to l...
MARK AS OVER ANNOTATED
Summary: ARL8B is a monomeric Arf-like small GTPase, so the heterotrimeric G protein activity term is not the best molecular-function annotation.
Reason: The cited evidence supports small-GTPase biology captured by GO:0003924 GTPase activity, which is already present and accepted; GO:0003925 is over-broad or semantically imprecise for ARL8B.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005765 lysosomal membrane
IDA
PMID:27808481
RNF167 targets Arl8B for degradation to regulate lysosome po...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0032418 lysosome localization
IDA
PMID:16537643
An N-terminally acetylated Arf-like GTPase is localised to l...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0032418 lysosome localization
IDA
PMID:27808481
RNF167 targets Arl8B for degradation to regulate lysosome po...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0042267 natural killer cell mediated cytotoxicity
IMP
PMID:24088571
Arf-like GTPase Arl8b regulates lytic granule polarization a...
KEEP AS NON CORE
Summary: natural killer cell mediated cytotoxicity is supported for NK cells, where ARL8B localizes to lytic granules and promotes polarization toward the immune synapse.
Reason: This is a well-supported lysosome-related organelle function in a specialized immune-cell context, not the general core function of ARL8B.
Supporting Evidence:
PMID:24088571
Arl8b drives the polarization of lytic granules and microtubule-organizing centers (MTOCs) toward the immune synapse
GO:0101004 cytolytic granule membrane
IDA
PMID:24088571
Arf-like GTPase Arl8b regulates lytic granule polarization a...
KEEP AS NON CORE
Summary: cytolytic granule membrane is supported for NK cells, where ARL8B localizes to lytic granules and promotes polarization toward the immune synapse.
Reason: This is a well-supported lysosome-related organelle function in a specialized immune-cell context, not the general core function of ARL8B.
Supporting Evidence:
PMID:24088571
Arl8b colocalizes with perforin, granzyme B, and LAMP-1, markers of lytic granules.
GO:0005515 protein binding
IPI
PMID:22172677
Arl8 and SKIP act together to link lysosomes to kinesin-1.
MARK AS OVER ANNOTATED
Summary: PLEKHM2/SKIP binding is central to ARL8B-dependent kinesin recruitment, but protein binding is too generic relative to the lysosome localization process annotation.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:22172677
Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
GO:0005765 lysosomal membrane
IDA
PMID:22172677
Arl8 and SKIP act together to link lysosomes to kinesin-1.
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0032418 lysosome localization
IMP
PMID:22172677
Arl8 and SKIP act together to link lysosomes to kinesin-1.
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0005764 lysosome
IDA
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
ACCEPT
Summary: lysosome is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0032418 lysosome localization
IDA
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0061909 autophagosome-lysosome fusion
IMP
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
ACCEPT
Summary: ARL8B contributes to autophagosome-lysosome fusion through PLEKHM1/HOPS-linked lysosomal contact sites.
Reason: The evidence is stronger for lysosomal tethering/fusion with autophagic cargo than for a separate autophagosome-positioning role.
Supporting Evidence:
PMID:28325809
Arl8b mediates recruitment of HOPS complex to PLEKHM1-positive vesicle contact sites.
PMID:28325809
Arl8b binding is crucial for PLEKHM1 to promote lysosomal degradation of endocytic and autophagic cargo.
GO:1902774 late endosome to lysosome transport
IMP
PMID:28325809
The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traff...
ACCEPT
Summary: late endosome to lysosome transport is supported by ARL8B loss-of-function cargo-delivery assays and HOPS recruitment evidence.
Reason: This captures ARL8B-dependent delivery of endocytic cargo to lysosomes, a core part of its endolysosomal trafficking role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
PMID:21802320
Arl8b was found to bind and recruit the VPS41 subunit of the HOPS (homotypic fusion and protein sorting) complex to lysosomes.
PMID:28325809
Arl8b, along with its effectors, orchestrates lysosomal transport and fusion.
GO:0001778 plasma membrane repair
IMP
PMID:29592961
Lysosome-Mediated Plasma Membrane Repair Is Dependent on the...
KEEP AS NON CORE
Summary: plasma membrane repair is supported in membrane injury and Mycobacterium infection models.
Reason: ARL8B-dependent lysosome exocytosis is real but context-dependent, so it should be retained as non-core rather than used to define the main gene function.
Supporting Evidence:
PMID:29592961
Arl8b is required for the process of plasma membrane repair in controlling the Ca2+-dependent exocytosis of lysosomes
PMID:29592961
Arl8b-depleted MDMs become necrotic after infection with H37Ra instead of apoptotic.
GO:0005764 lysosome
IDA
PMID:29592961
Lysosome-Mediated Plasma Membrane Repair Is Dependent on the...
ACCEPT
Summary: lysosome is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0032418 lysosome localization
IMP
PMID:29592961
Lysosome-Mediated Plasma Membrane Repair Is Dependent on the...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:1990927 calcium ion regulated lysosome exocytosis
IMP
PMID:29592961
Lysosome-Mediated Plasma Membrane Repair Is Dependent on the...
KEEP AS NON CORE
Summary: calcium ion regulated lysosome exocytosis is supported in membrane injury and Mycobacterium infection models.
Reason: ARL8B-dependent lysosome exocytosis is real but context-dependent, so it should be retained as non-core rather than used to define the main gene function.
Supporting Evidence:
PMID:29592961
Arl8b is required for the process of plasma membrane repair in controlling the Ca2+-dependent exocytosis of lysosomes
GO:0002747 antigen processing and presentation following phagocytosis
IMP
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
KEEP AS NON CORE
Summary: antigen processing and presentation following phagocytosis is supported by immune-cell lysosomal trafficking studies but is context-specific.
Reason: ARL8B controls delivery of antigen-containing cargo to lysosomal compartments; antigen presentation is a downstream immune-cell outcome rather than the core molecular role.
Supporting Evidence:
PMID:21802320
phagosome to lysosome delivery and fusion were delayed by Arl8b silencing resulting in a defect in microbial killing.
GO:0005515 protein binding
IPI
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
MARK AS OVER ANNOTATED
Summary: VPS41/HOPS binding supports ARL8B-mediated lysosomal cargo delivery, but protein binding is too broad and should not be treated as a useful molecular function term.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:21802320
Arl8b was found to bind and recruit the VPS41 subunit of the HOPS (homotypic fusion and protein sorting) complex to lysosomes.
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
GO:0005525 GTP binding
IMP
PMID:16650381
The Arf-family protein, Arl8b, is involved in the spatial di...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTP binding annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005764 lysosome
IMP
PMID:16650381
The Arf-family protein, Arl8b, is involved in the spatial di...
ACCEPT
Summary: lysosome is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0005764 lysosome
IDA
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
ACCEPT
Summary: lysosome is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0019003 GDP binding
IMP
PMID:16650381
The Arf-family protein, Arl8b, is involved in the spatial di...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GDP binding annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
GO:0032418 lysosome localization
IMP
PMID:16650381
The Arf-family protein, Arl8b, is involved in the spatial di...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0032418 lysosome localization
IMP
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0090117 endosome to lysosome transport of low-density lipoprotein particle
IMP
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
ACCEPT
Summary: endosome to lysosome transport of low-density lipoprotein particle is supported by ARL8B loss-of-function cargo-delivery assays and HOPS recruitment evidence.
Reason: This captures ARL8B-dependent delivery of endocytic cargo to lysosomes, a core part of its endolysosomal trafficking role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
GO:0090385 phagosome-lysosome fusion
IMP
PMID:21802320
Lysosomal trafficking, antigen presentation, and microbial k...
KEEP AS NON CORE
Summary: Phagosome-lysosome fusion is directly supported in host-defense assays, but it is a context-specific branch of ARL8B lysosomal trafficking.
Reason: The annotation is biologically sound, but phagocytic killing is not the broad core role of ARL8B across cell types.
Supporting Evidence:
PMID:21802320
phagosome to lysosome delivery and fusion were delayed by Arl8b silencing resulting in a defect in microbial killing.
GO:0002505 antigen processing and presentation of polysaccharide antigen via MHC class II
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: antigen processing and presentation of polysaccharide antigen via MHC class II is supported by immune-cell lysosomal trafficking studies but is context-specific.
Reason: ARL8B controls delivery of antigen-containing cargo to lysosomal compartments; antigen presentation is a downstream immune-cell outcome rather than the core molecular role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
GO:1902774 late endosome to lysosome transport
ISS
GO_REF:0000024
ACCEPT
Summary: late endosome to lysosome transport is supported by ARL8B loss-of-function cargo-delivery assays and HOPS recruitment evidence.
Reason: This captures ARL8B-dependent delivery of endocytic cargo to lysosomes, a core part of its endolysosomal trafficking role.
Supporting Evidence:
PMID:21802320
Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
PMID:21802320
Arl8b was found to bind and recruit the VPS41 subunit of the HOPS (homotypic fusion and protein sorting) complex to lysosomes.
PMID:28325809
Arl8b, along with its effectors, orchestrates lysosomal transport and fusion.
GO:0005515 protein binding
IPI
PMID:25898167
BORC, a multisubunit complex that regulates lysosome positio...
MARK AS OVER ANNOTATED
Summary: BORCS5/BORC interaction supports ARL8B lysosomal recruitment and positioning, but generic protein binding is not curator-informative.
Reason: ARL8B functions as a regulated small GTPase that recruits specific effectors to endolysosomal membranes; a generic protein binding annotation obscures that biology and is therefore over-annotated.
Supporting Evidence:
PMID:25898167
BORC functions to recruit Arl8 to lysosomes, thereby initiating a chain of interactions that promotes microtubule-guided transport of lysosomes toward the cell periphery.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0005765 lysosomal membrane
IDA
PMID:25898167
BORC, a multisubunit complex that regulates lysosome positio...
ACCEPT
Summary: lysosomal membrane is a core localization for ARL8B based on direct localization studies and UniProt synthesis.
Reason: ARL8B acts from lysosomal/endolysosomal membranes to recruit effectors controlling motility, tethering, fusion, and cargo sorting.
Supporting Evidence:
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0032418 lysosome localization
IMP
PMID:25898167
BORC, a multisubunit complex that regulates lysosome positio...
ACCEPT
Summary: Lysosome localization is the best-supported core biological process for ARL8B.
Reason: Multiple independent studies show ARL8B-dependent peripheral/anterograde lysosome positioning through BORC, SKIP/kinesin, and regulation by RNF167.
Supporting Evidence:
PMID:16537643
Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
PMID:22172677
Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
PMID:25898167
BORC acts at an early stage, recruiting Arl8b to the lysosomal membrane and therefore enabling coupling to the SKIP-Kinesin-1 complex
GO:0016020 membrane
HDA
PMID:19946888
Defining the membrane proteome of NK cells.
MARK AS OVER ANNOTATED
Summary: Generic membrane localization from high-throughput NK-cell membrane proteomics is much less informative than lysosomal membrane localization.
Reason: The more specific lysosomal/cytolytic-granule membrane annotations should carry this biology; generic membrane is over-annotated.
Supporting Evidence:
PMID:19946888
Defining the membrane proteome of NK cells.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0070062 extracellular exosome
HDA
PMID:19056867
Large-scale proteomics and phosphoproteomics of urinary exos...
MARK AS OVER ANNOTATED
Summary: Extracellular exosome comes from broad high-throughput proteomics and is not a defining ARL8B localization or function.
Reason: This does not fit the strong mechanistic consensus that ARL8B functions on endolysosomal/lysosomal membranes.
Supporting Evidence:
PMID:19056867
Large-scale proteomics and phosphoproteomics of urinary exosomes.
file:human/ARL8B/ARL8B-uniprot.txt
Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility
GO:0003924 GTPase activity
NAS
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTPase activity annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005525 GTP binding
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GTP binding annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16537643
Arl8a and Arl8b (also known as Arl10b/c and Gie1/2), localise to lysosomes in
GO:0005737 cytoplasm
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
KEEP AS NON CORE
Summary: cytoplasm comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0007059 chromosome segregation
IMP
PMID:14871887
Drosophila Topors is a RING finger-containing protein that f...
KEEP AS NON CORE
Summary: The term is supported by the ARL8/GIE chromosome-segregation study, but the seeded GOA original PMID points to an unrelated Drosophila Topors paper.
Reason: Keep as non-core because PMID:15331635 supports a mitotic phenotype for GIE/ARL8 proteins. The original_reference_id is retained as fetched GOA provenance, while the corrected supporting ARL8B reference is recorded in additional_reference_ids and the upstream source should be checked.
Supporting Evidence:
PMID:14871887
Drosophila Topors is a RING finger-containing protein that functions as a ubiquitin-protein isopeptide ligase for the hairy basic helix-loop-helix repressor protein.
PMID:15331635
Expression of dominant-negative Gie mutants in mammalian cells or knockdown of Gie transcripts using RNA interference in Drosophila S2 cells induced abnormal morphology in the chromosome segregation.
GO:0019003 GDP binding
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
ACCEPT
Summary: ARL8B is a small Arf-like GTPase; the GDP binding annotation is consistent with direct biochemical and sequence evidence.
Reason: GTP binding/hydrolysis and small G-protein switching are core molecular features of ARL8B that underlie effector recruitment on endolysosomal membranes.
Supporting Evidence:
PMID:15331635
Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases
PMID:16650381
GTP-restricted mutant Arl8b localizes to lysosomes and causes their redistribution to the periphery of the cell and into membrane projections.
GO:0030496 midbody
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
KEEP AS NON CORE
Summary: midbody comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0043014 alpha-tubulin binding
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
KEEP AS NON CORE
Summary: alpha-tubulin binding comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0048487 beta-tubulin binding
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
KEEP AS NON CORE
Summary: beta-tubulin binding comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.
GO:0051233 spindle midzone
IDA
PMID:15331635
Novel small GTPase subfamily capable of associating with tub...
KEEP AS NON CORE
Summary: spindle midzone comes from the early GIE/ARL8B microtubule and mitosis study.
Reason: This appears experimentally supported but peripheral to the dominant lysosomal small-GTPase role established by later work.
Supporting Evidence:
PMID:15331635
Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis.

Core Functions

ARL8B is an endolysosomal small GTPase that uses GTP-dependent effector recruitment to control lysosome positioning and lysosome-centered cargo delivery. Its best-supported core role is coordinating lysosome movement and contact/fusion machinery, including BORC/SKIP-kinesin positioning and PLEKHM1/HOPS-dependent delivery of endocytic, phagocytic, and autophagic cargo to lysosomes.

Supporting Evidence:
  • PMID:16537643
    Overexpression of Arl8a or Arl8b results in a microtubule-dependent redistribution of lysosomes towards the cell periphery.
  • PMID:22172677
    Thus, Arl8 binding to SKIP provides a link from lysosomal membranes to plus-end-directed motility.
  • PMID:21802320
    Arl8b silencing resulted in a delay in delivery of fluid phase dextran, receptor-internalized low-density lipoprotein (LDL), and CD1 cargo to lysosomes.
  • PMID:28325809
    Arl8b binding is crucial for PLEKHM1 to promote lysosomal degradation of endocytic and autophagic cargo.
  • PMID:25898167
    BORC functions to recruit Arl8 to lysosomes, thereby initiating a chain of interactions that promotes microtubule-guided transport of lysosomes toward the cell periphery.

References

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Suggested Questions for Experts

Q: Should ARL8B be annotated directly to GO:0061906 autophagosome localization from the PN HOPS-BORC bridging projection, or is the current direct evidence better captured by lysosome localization and autophagosome-lysosome fusion?

Q: Can the upstream reference for the GO:0007059 chromosome segregation annotation be corrected from PMID:14871887 to the ARL8B/GIE study PMID:15331635?

Q: Which ARL8B effector branch should be considered core for general gene-product curation versus cell-type-specific extensions such as NK-cell granule polarization, Mtb membrane repair, or beta-coronavirus egress?

Q: Should ARL8B be annotated to retrograde lysosome transport given that it now has two distinct retrograde effector branches (DENND6A/Rab34/RILP/dynein and RUFY3/RUFY4/dynein-dynactin), and how should these be distinguished from the better-established anterograde SKIP/kinesin role?

Suggested Experiments

Experiment: Separate ARL8B lysosome-positioning effects from autophagosome-positioning effects by live imaging of autophagosomes and lysosomes after ARL8B depletion or effector-selective rescue.

Hypothesis: The PN autophagosome-localization signal is mainly an indirect consequence of ARL8B-dependent lysosome positioning and HOPS-mediated fusion rather than direct autophagosome positioning.

Experiment: Use effector-binding mutants of ARL8B to compare PLEKHM2/SKIP, PLEKHM1/HOPS, VPS41, RUFY1, RUFY3/4, and DENND6A outputs in the same cellular background.

Hypothesis: Distinct ARL8B effector interfaces partition lysosome positioning, cargo delivery, and lysosome exocytosis functions.

Experiment: Test whether ARL8B-dependent retrograde lysosome transport requires the DENND6A/Rab34/RILP/dynein cascade by measuring nutrient-dependent juxtanuclear lysosome repositioning and autophagic flux after depletion of DENND6A, Rab34, or RILP versus RUFY3/4.

Hypothesis: ARL8B initiates retrograde lysosome transport through at least two parallel dynein-recruiting branches (DENND6A/Rab34/RILP and RUFY3/4), and these jointly regulate nutrient-responsive lysosome positioning and autophagy.

Tags

proteostasis autophagy-lysosome-pathway lysosome-positioning pn-projection-reviewed

Deep Research

Falcon

(ARL8B-deep-research-falcon.md)

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πŸ“š Additional Documentation

Notes

(ARL8B-notes.md)

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Pn Notes

(ARL8B-pn-notes.md)

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πŸ“„ View Raw YAML

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