6vrf
ADP bound TTBK2 kinase domain
Structural highlights
DiseaseTTBK2_HUMAN Spinocerebellar ataxia type 11. The disease is caused by mutations affecting the gene represented in this entry. FunctionTTBK2_HUMAN Serine/threonine kinase that acts as a key regulator of ciliogenesis: controls the initiation of ciliogenesis by binding to the distal end of the basal body and promoting the removal of CCP110, which caps the mother centriole, leading to the recruitment of IFT proteins, which build the ciliary axoneme. Has some substrate preference for proteins that are already phosphorylated on a Tyr residue at the +2 position relative to the phosphorylation site. Able to phosphorylate tau on serines in vitro.[1] [2] Publication Abstract from PubMedTau-tubulin kinase 1 (TTBK1) is a CNS-specific, kinase that has been implicated in the pathological phosphorylation of tau in Alzheimer's Disease (AD) and Frontotemporal Dementia (FTD). TTBK1 is a challenging therapeutic target because it shares a highly conserved catalytic domain with its homolog, TTBK2, a ubiquitously expressed kinase genetically linked to the disease spinocerebellar ataxia type 11. The present study attempts to elucidate the functional distinctions between the TTBK isoforms and increase our understanding of them as distinct targets for the treatment of neurodegenerative disease. We demonstrate that in cortical neurons, TTBK1, not TTBK2, is the isoform responsible for tau phosphorylation at epitopes enriched in tauopathies such as Serine 422. In addition, although our elucidation of the crystal structure of the TTBK2 kinase domain indicates almost identical structural similarity with TTBK1, biochemical and cellular assays demonstrate that the enzymatic activity of these two proteins is regulated by a combination of unique extra-catalytic sequences and autophosphorylation events. Finally, we have identified an unbiased list of neuronal interactors and phosphorylation substrates for TTBK1 and TTBK2 that highlight the unique cellular pathways and functional networks that each isoform is involved in. This data address an important gap in knowledge regarding the implications of targeting TTBK kinases and may prove valuable in the development of potential therapies for disease. Mechanisms of Regulation and Diverse Activities of Tau-Tubulin Kinase (TTBK) Isoforms.,Bao C, Bajrami B, Marcotte DJ, Chodaparambil JV, Kerns HM, Henderson J, Wei R, Gao B, Dillon GM Cell Mol Neurobiol. 2021 May;41(4):669-685. doi: 10.1007/s10571-020-00875-6. Epub, 2020 May 18. PMID:32424773[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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