TLK1
TLK1 (tousled like kinase 1, also known as KIAA0137 or PKU-BETA) is a nuclear serine/threonine kinase that may regulate chromatin assembly. Its activity is tied to the cell cycle and is reduced by DNA damage and by blocked DNA replication. Browse Assay Genie's current range of TLK1 research reagents below, or read on for the biology behind the target.
TLK1 is a serine/threonine-protein kinase that belongs to the protein kinase superfamily and the Ser/Thr protein kinase family. It is thought to take part in the regulation of chromatin assembly. The protein is active only when phosphorylated, and this phosphorylation depends on the cell cycle, with maximal activity during S phase. Its catalytic activity falls after DNA damage and after blockage of DNA replication. In vitro, TLK1 phosphorylates histone H3 at Ser-10.
TLK1 responds rapidly to DNA double-strand breaks. During S phase, breaks cause a rapid and transient inhibition of the kinase through phosphorylation. This inhibition depends on the cell cycle checkpoint and the ATM pathway, and it appears to regulate processes involved in chromatin assembly. One isoform, isoform 3, phosphorylates the t-SNARE SNAP23 and enhances its stability, which augments its assembly with syntaxin. Isoform 3 also protects cells from ionising radiation by facilitating the repair of double-strand breaks.
The TLK1 gene is a member of the tousled like kinase family, which also includes TLK2, and it has three reported transcript variants that encode different isoforms. The mouse ortholog is Tlk1. The names KIAA0137 and PKU-BETA are alternative designations for the same gene, and the earlier HGNC name was tousled-like kinase 1. Researchers studying chromatin assembly, S-phase checkpoints and the DNA damage response use TLK1 as a model for how kinase activity is coupled to genome integrity.
TLK1 may regulate chromatin assembly, and it phosphorylates histone H3 at Ser-10 in vitro, making it a useful kinase for chromatin biology.
TLK1 activity is inhibited after double-strand breaks in an ATM-dependent manner, linking the kinase to checkpoint signalling during S phase.
Isoform 3 protects cells from ionising radiation by facilitating the repair of double-strand breaks, a focus for repair studies.
TLK1 is active only when phosphorylated, with maximal activity in S phase, so it is studied as a cell cycle-dependent kinase.
TLK1 is a nuclear serine/threonine kinase that may regulate chromatin assembly. It is active when phosphorylated, peaking in S phase, and is inhibited after DNA damage. In vitro it phosphorylates histone H3 at Ser-10. Isoform 3 also phosphorylates SNAP23 and aids repair of double-strand breaks.
TLK1 is also called tousled-like kinase 1, KIAA0137 and PKU-BETA. Its UniProt name is serine/threonine-protein kinase tousled-like 1. Three transcript variants encode different isoforms, and isoform 3 has the described roles in SNAP23 stabilisation and double-strand break repair.
TLK1 belongs to the tousled like kinase family, alongside TLK2, and to the Ser/Thr protein kinase family. Mouse has an ortholog, Tlk1. Check the datasheet of any product for its validated reactivity.
TLK2, the other member of the tousled like kinase family, is a related target with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9UKI8; product specifications from Assay Genie datasheets.