ADP-ribosylation factor-like protein 8B (EC 3.6.5.2) (ADP-ribosylation factor-like protein 10C) (Novel small G protein indispensable for equal chromosome segregation 1)
1_MLALI 6_ SRLLD 11_ WFRSL 16_ FWKEE 21_ MELTL 26_ VGLQY 31_ SGKTT 36_ FVNVI 41_ ASGQF 46_ SEDMI 51_ PTVGF 56_ NMRKV 61_ TKGNV 66_ TIKIW 71_ DIGGQ 76_ PRFRS 81_ MWERY 86_ CRGVN 91_ AIVYM 96_ IDAAD 101_ REKIE 106_ ASRNE 111_ LHNLL 116_ DKPQL 121_ QGIPV 126_ LVLGN 131_ KRDLP 136_ NALDE 141_ KQLIE 146_ KMNLS 151_ AIQDR 156_ EICCY 161_ SISCK 166_ EKDNI 171_ DITLQ 176_ WLIQH 181_SKSRR
1: Small GTPase which cycles between active GTP-bound and inactive GDP-bound states (PubMed:15331635, PubMed:16537643). In its active state, binds to a variety of effector proteins playing a key role in the regulation of lysosomal positioning which is important for nutrient sensing, natural killer cell-mediated cytotoxicity and antigen presentation. Along with its effectors, orchestrates lysosomal transport and fusion (PubMed:16537643, PubMed:16650381, PubMed:25898167, PubMed:27808481, PubMed:28325809). Localizes specifically to lysosomal membranes and mediates anterograde lysosomal motility by recruiting PLEKHM2, which in turn recruits the motor protein kinesin-1 on lysosomes. Required for lysosomal and cytolytic granule exocytosis (PubMed:22172677, PubMed:24088571, PubMed:29592961). Critical factor involved in NK cell-mediated cytotoxicity. Drives the polarization of cytolytic granules and microtubule-organizing centers (MTOCs) toward the immune synapse between effector NK lymphocytes and target cells (PubMed:24088571). In neurons, mediates the anterograde axonal long-range transport of presynaptic lysosome-related vesicles required for presynaptic biogenesis and synaptic function (By similarity). Also acts as a regulator of endosome to lysosome trafficking pathways of special significance for host defense (PubMed:21802320). Recruits RUFY1 onto early endosomes regulating endosomes to trans-Golgi network proteins retrieval (PubMed:36282215). Regulates cargo trafficking to lysosomes by binding to PLEKHM1 and recruiting the HOPS subunit VPS41, resulting in functional assembly of the HOPS complex on lysosomal membranes (PubMed:16537643, PubMed:25908847). Plays an important role in cargo delivery to lysosomes for antigen presentation and microbial killing. Directs the intersection of CD1d with lipid antigens in lysosomes, and plays a role in intersecting phagosomes with lysosomes to generate phagolysosomes that kill microbes (PubMed:21802320, PubMed:25908847). Involved in the process of MHC II presentation. Regulates the delivery of antigens to lysosomes and the formation of MHC II-peptide complexes through the recruitment of the HOPS complex to lysosomes allowing the fusion of late endosomes to lysosomes (By similarity). May play a role in chromosome segregation (PubMed:15331635)
2: (Microbial infection) During Mycobacterium tuberculosis (Mtb) infection, is required for plasma membrane repair by controlling the exocytosis of lysosomes in macrophages. ARL8B secretion pathway is crucial to control the type of cell death of the M.tuberculosis-infected macrophages, distinguishing avirulent from virulent Mtb induced necrotic cell death
3: (Microbial infection) During infection, coronaviruses such as SARS-CoV-2 and the chaperone HSPA5/GRP78 are probably co-released through ARL8B-dependent lysosomal exocytic pathway for unconventional egress