VRK3
serine/threonine-protein kinase VRK3 (Serine/threonine-protein pseudokinase VRK3) (Vaccinia-related kinase 3)
Publications[править]
Vaccinia-related kinase 3 (VRK3), previously characterized as a direct activator of vaccinia H1-related (VHR) phosphatase, inactivates extracellular signal-regulated kinase (ERK) in the nucleus of neuronal cells. Here we show that VRK3 is expressed in various other rodent tissues and in embryos, and regulates VHR phosphatase activity in these tissues. We observed colocalization of VRK3 and VHR in the testis tissue and could detect protein complex containing VRK3, VHR and ERK in immunoprecipitation analysis. Notably, the addition of recombinant VRK3 protein to total protein lysates, obtained either from adult tissues or embryos, enhanced the phosphatase activity of VHR, but not the activity of MKP3. The results further indicate that the VHR-VRK3 complex is a phosphatase-active form. In addition, we found that VRK3 can regulate EGF-induced cellular growth signaling that is mediated by ERK activation. Our results suggest that in addition to neuronal cells, various other rodent adult tissues and embryos possess a common signaling mechanism which is involved in an indirect regulation of ERK activity by VRK3-mediated VHR activity.
MeSH Terms
- Aging
- Animals
- Cell Line
- Dual Specificity Phosphatase 3
- Enzyme Activation
- Extracellular Signal-Regulated MAP Kinases
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- MAP Kinase Signaling System
- Male
- Mice
- Organ Specificity
- Protein Binding
- Protein-Serine-Threonine Kinases
- RNA, Small Interfering
- Rats