Recombinant Human Serine/threonine-protein kinase TBK1 (TBK1), partial

Function

Serine/threonine kinase that plays an essential role in regulating inflammatory responses to foreign agents (PubMed:10581243, PubMed:11839743, PubMed:12692549, PubMed:12702806, PubMed:14703513, PubMed:15367631, PubMed:15485837, PubMed:18583960, PubMed:21138416, PubMed:23453971, PubMed:23453972, PubMed:23746807, PubMed:25636800, PubMed:26611359, PubMed:32404352, PubMed:34363755, PubMed:32298923). Following activation of toll-like receptors by viral or bacterial components, associates with TRAF3 and TANK and phosphorylates interferon regulatory factors (IRFs) IRF3 and IRF7 as well as DDX3X (PubMed:12692549, PubMed:12702806, PubMed:14703513, PubMed:15367631, PubMed:18583960, PubMed:25636800). This activity allows subsequent homodimerization and nuclear translocation of the IRFs leading to transcriptional activation of pro-inflammatory and antiviral genes including IFNA and IFNB (PubMed:12702806, PubMed:15367631, PubMed:25636800, PubMed:32972995). In order to establish such an antiviral state, TBK1 form several different complexes whose composition depends on the type of cell and cellular stimuli (PubMed:23453971, PubMed:23453972, PubMed:23746807). Plays a key role in IRF3 activation: acts by first phosphorylating innate adapter proteins MAVS, STING1 and TICAM1 on their pLxIS motif, leading to recruitment of IRF3, thereby licensing IRF3 for phosphorylation by TBK1 (PubMed:25636800, PubMed:30842653, PubMed:37926288). Phosphorylated IRF3 dissociates from the adapter proteins, dimerizes, and then enters the nucleus to induce expression of interferons (PubMed:25636800). Thus, several scaffolding molecules including FADD, TRADD, MAVS, AZI2, TANK or TBKBP1/SINTBAD can be recruited to the TBK1-containing-complexes (PubMed:21931631). Under particular conditions, functions as a NF-kappa-B effector by phosphorylating NF-kappa-B inhibitor alpha/NFKBIA, IKBKB or RELA to translocate NF-Kappa-B to the nucleus (PubMed:10783893, PubMed:15489227). Restricts bacterial proliferation by phosphorylating the autophagy receptor OPTN/Optineurin on 'Ser-177', thus enhancing LC3 binding affinity and antibacterial autophagy (PubMed:21617041). Phosphorylates SMCR8 component of the C9orf72-SMCR8 complex, promoting autophagosome maturation (PubMed:27103069). Phosphorylates ATG8 proteins MAP1LC3C and GABARAPL2, thereby preventing their delipidation and premature removal from nascent autophagosomes (PubMed:31709703). Seems to play a role in energy balance regulation by sustaining a state of chronic, low-grade inflammation in obesity, which leads to a negative impact on insulin sensitivity (By similarity). Attenuates retroviral budding by phosphorylating the endosomal sorting complex required for transport-I (ESCRT-I) subunit VPS37C (PubMed:21270402). Phosphorylates Borna disease virus (BDV) P protein (PubMed:16155125). Plays an essential role in the TLR3- and IFN-dependent control of herpes virus HSV-1 and HSV-2 infections in the central nervous system (PubMed:22851595). Acts both as a positive and negative regulator of the mTORC1 complex, depending on the context: activates mTORC1 in response to growth factors by catalyzing phosphorylation of MTOR, while it limits the mTORC1 complex by promoting phosphorylation of RPTOR (PubMed:29150432, PubMed:31530866). Acts as a positive regulator of the mTORC2 complex by mediating phosphorylation of MTOR, leading to increased phosphorylation and activation of AKT1 (By similarity). Phosphorylates and activates AKT1 (PubMed:21464307). Involved in the regulation of TNF-induced RIPK1-mediated cell death, probably acting via CYLD phosphorylation that in turn controls RIPK1 ubiquitination status (PubMed:34363755). Also participates in the differentiation of T follicular regulatory cells together with the receptor ICOS (PubMed:27135603)

Subcellular Location

Cytoplasm

Disease Association

Glaucoma 1, open angle, P (GLC1P) : A form of primary open angle glaucoma (POAG). POAG is characterized by a specific pattern of optic nerve and visual field defects. The angle of the anterior chamber of the eye is open, and usually the intraocular pressure is increased. However, glaucoma can occur at any intraocular pressure. The disease is generally asymptomatic until the late stages, by which time significant and irreversible optic nerve damage has already taken place. GLC1P is characterized by early onset, thin central corneas and low intraocular pressure. [The disease may be caused by variants affecting the gene represented in this entry. A copy number variation on chromosome 12q14 consisting of a 300 kb duplication that includes TBK1, XPOT, RASSF3 and GNS has been found in individuals affected by glaucoma. TBK1 is the most likely candidate for the disorder (PubMed:21447600)] | Frontotemporal dementia and/or amyotrophic lateral sclerosis 4 (FTDALS4) : A neurodegenerative disorder characterized by frontotemporal dementia and/or amyotrophic lateral sclerosis in affected individuals. There is high intrafamilial variation. Frontotemporal dementia is characterized by frontal and temporal lobe atrophy associated with neuronal loss, gliosis, and dementia. Patients exhibit progressive changes in social, behavioral, and/or language function. Amyotrophic lateral sclerosis is characterized by the death of motor neurons in the brain, brainstem, and spinal cord, resulting in fatal paralysis. [The disease is caused by variants affecting the gene represented in this entry] | Encephalopathy, acute, infection-induced, 8, herpes-specific (IIAE8) : A rare, often fatal complication of herpes simplex infection, caused by virus spreading in the central nervous system. Disease manifestations include low-grade fever, severe headache, nausea, vomiting, and lethargy. Neurological features include confusion, acute memory disturbances, disorientation, behavioral changes, hemiparesis and seizures. [Disease susceptibility is associated with variants affecting the gene represented in this entry] | Autoinflammation with arthritis and vasculitis (AIARV) : An autosomal recessive disorder characterized by onset of chronic and systemic autoinflammation in infancy or early childhood. Affected individuals have recurrent fever, erythematous skin rashes, vasculitis, oral aphthous lesions, and polyarthritis. Additional variable features are poor overall growth, microcytic anemia, mild intellectual disability, and seizures. [The disease is caused by variants affecting the gene represented in this entry]

Tissue Specificity

Ubiquitous with higher expression in testis. Expressed in the ganglion cells, nerve fiber layer and microvasculature of the retina

Subunit

(Microbial infection) Interacts (via N-terminus) with Severe fever with thrombocytopenia virus (SFTSV) NSs; this interaction antagonizes TBK1 phosphorylation and sequesters TBK1 in NSs-induced cytoplasmic inclusion bodies thereby inhibiting the IFN responses

• Pomerantz J.L. et al. NF-kB activation by a signaling complex containing TRAF2, TANK, and TBK1, a novel IKK-related kinase. — EMBO J. (1999)
• Tojima Y. et al. NAK is an IkappaB kinase-activating kinase. — Nature (2000)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• Mural R.J. et al. PubMed: CI-5GBDQ6B103N1E (JUL-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Kishore N. et al. IKK-i and TBK-1 are enzymatically distinct from the homologous enzyme IKK-2: comparative analysis of recombinant human IKK-i, TBK-1, and IKK-2. — J. Biol. Chem. (2002)
• Sato S. et al. Toll/IL-1 receptor domain-containing adapter inducing IFN-beta (TRIF) associates with TNF receptor-associated factor 6 and TANK-binding kinase 1, and activates two distinct transcription factors, NF-kappa B and IFN-regulatory factor-3, in the Toll-like receptor signaling. — J. Immunol. (2003)
• Fitzgerald K.A. et al. IKKepsilon and TBK1 are essential components of the IRF3 signaling pathway. — Nat. Immunol. (2003)