DAP Kinase 3, (Death-Associated Protein Kinase 3 (Internal Epitope) (DAPK3) Antibody – Rabbit Polyclonal

Function: Serine/threonine kinase which is involved in the regulation of apoptosis, autophagy, transcription, translation, actin cytoskeleton reorganization, cell motility, smooth muscle contraction, and mitosis, particularly cytokinesis. Regulates both type I apoptotic and type II autophagic cell deaths signal, depending on the cellular setting. The former is caspase-dependent, while the latter is caspase-independent and is characterized by the accumulation of autophagic vesicles. Regulates myosin phosphorylation in both smooth muscle and non-muscle cells. In smooth muscle, regulates myosin either directly by phosphorylating MYL12B and MYL9 or through inhibition of smooth muscle myosin phosphatase (SMPP1M) via phosphorylation of PPP1R12A, and the inhibition of SMPP1M functions to enhance muscle responsiveness to Ca2+ and promote a contractile state. Enhances transcription from AR-responsive promoters in a hormone- and kinase-dependent manner. Phosphorylates STAT3 and enhances its transcriptional activity. Positively regulates the canonical Wnt/beta-catenin signaling through interaction with NLK and TCF7L2. Can disrupt the NLK-TCF7L2 complex thereby influencing the phosphorylation of TCF7L2 by NLK. Phosphorylates histone H3 on 'Thr-11' at centromeres during mitosis. Involved in the formation of promyelocytic leukemia protein nuclear body (PML-NB), one of many subnuclear domains in the eukaryotic cell nucleus, and which is involved in oncogenesis and viral infection. Phosphorylates RPL13A on 'Ser-77' upon interferon-gamma activation which is causing RPL13A release from the ribosome, its association with the GAIT complex and its subsequent involvement in transcript-selective translation inhibition. Ref.2 Ref.5 Ref.7 Ref.8 Ref.9 Ref.10 Ref.12 Ref.17 Ref.20 Ref.21 Ref.23 Ref.24Isoform 2 can phosphorylate myosin, PPP1R12A and MYL12B. Ref.2 Ref.5 Ref.7 Ref.8 Ref.9 Ref.10 Ref.12 Ref.17 Ref.20 Ref.21 Ref.23 Ref.24

Catalytic activity: ATP + a protein = ADP + a phosphoprotein. Ref.2

Cofactor: Magnesium. Ref.2

Enzyme regulation: Inhibited by pyridone 6 (K00225), a potent, ATP-competitive inhibitor. Phosphorylation at Thr-180, Thr-225 and Thr-265 is essential for activity. Oligomerization is required for full enzymatic activity. Ref.11 Ref.14 Ref.17

Subunit structure: Monomer and homotrimer. Can also exist as homodimer or form heterodimers with ATF4. Homodimerization is required for activation segment autophosphorylation Both interactions require an intact leucine zipper domain and oligomerization is required for full enzymatic activity. Also binds to DAXX and PAWR, possibly in a ternary complex which plays a role in caspase activation. According to Ref.18, does not interact with PARW. Interacts with AATF, CDC5L, UBE2D1, UBE2D2 AND UBE2D3. Interacts with AR and this interaction is enhanced by AATF. Interacts (via leucine zipper) with TCP10L (via leucine zipper). Interacts (via kinase domain) with DAPK1 (via kinase domain). Interacts with STAT3, NLK and TCF7L2. Isoform 1 and isoform 2 can interact with myosin and PPP1R12A. Ref.5 Ref.7 Ref.9 Ref.11 Ref.12 Ref.13 Ref.18 Ref.20 Ref.21 Ref.23 Ref.24

Subcellular location: Nucleus. Cytoplasm Ref.5 Ref.6 Ref.8 Ref.9 Ref.13 Ref.18 Ref.20 Ref.22. Nucleus › PML body. Chromosome › centromere. Cytoplasm › cytoskeleton › centrosome. Note: The phosphorylated form is anchored in the cytoplasm and/or prevented from being shuttled to the nucleus, whereas nuclear translocation or retention is maximal when it is not phosphorylated. Phosphorylation at Thr-299 promotes cytoplasmic localization. Relocates to the cytoplasm on binding PAWR where the complex appears to interact with actin filaments. Localizes to promyelocytic leukemia protein nuclear bodies (PML-NBs). Associated: with the centrosomes throughout the mitotic cell cycle, with the centromeres from prophase to anaphase and with the contractile ring during cytokinesis. Ref.5 Ref.6 Ref.8 Ref.9 Ref.13 Ref.18 Ref.20 Ref.22Isoform 2: Nucleus. Cytoplasm Ref.5 Ref.6 Ref.8 Ref.9 Ref.13 Ref.18 Ref.20 Ref.22.

Tissue specificity: Isoform 2 is expressed in the bladder smooth muscle. Ref.5

Post-translational modification: Ubiquitinated. Ubiquitination mediated by the UBE2D3 E3 ligase does not lead to proteasomal degradation, but influences promyelocytic leukemia protein nuclear bodies (PML-NBs) formation in the nucleus.The phosphorylation status is critical for: its intracellular localization, ability to oligomerize and its activity. The phosphorylated form is anchored in the cytoplasm and/or prevented from being shuttled to the nucleus, whereas nuclear translocation or retention is maximal when it is not phosphorylated. Phosphorylation increases the trimeric form, and its dephosphorylation shifts the equilibrium towards the monomeric form. Phosphorylation at Thr-180, Thr-225 and Thr-265 is essential for activity. Phosphorylation at Thr-299 promotes cytoplasmic localization. A species-specific loss of a key phosphorylation site in murine DAPK3 seems to direct it to the nucleus, while the presence of the Thr-299 site in human DAPK3 correlates with cytoplasmic localization. Both isoform 1 and isoform 2 can undergo autophosphorylation. Ref.5 Ref.9 Ref.11 Ref.14 Ref.16 Ref.17 Ref.22

Miscellaneous: The murine DAPK3 protein differs from the human ortholog, losing an important phosphorylation site and displaying distinct altered cellular localization. The murine protein localizes only to the nucleus while the human protein shows both nuclear and cytoplasmic localization. A different protein interaction capacity, with an important protein partner in the apoptosis pathway (PAWR), evolved in the murine system to maintain the basic membrane blebbing function in the apoptosis pathway.

Sequence similarities: Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. DAP kinase subfamily.Contains 1 protein kinase domain.

Biophysicochemical propertiesKinetic parameters:KM=12 µM for myosin (isoform 2) Ref.5KM=6.2 µM for myosin (isoform 1)KM=73 µM for MYL12B (isoform 2)KM=10.4 µM for MYL12B (isoform 1)Vmax=248 nmol/min/mg enzyme toward myosin (isoform 2)Vmax=120 nmol/min/mg enzyme toward myosin (isoform 1)Vmax=1.3 µmol/min/mg enzyme toward MYL12B (isoform 2)Vmax=271 nmol/min/mg enzyme toward MYL12B (isoform 1)