Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.11.18 (MAP)
 7,412 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein phosphatases (PPs) and protein kinases (PKs) regulate numerous developmental, defense, and phytohormone signaling processes in plants. However, the underlying regulatory mechanism governing biosynthesis of specialized metabolites, such as alkaloids, by the combined effects of PPs and PKs is insufficiently understood. Here, we report the characterization of a group B protein phosphatase type 2C (PP2C), NtPP2C2b, that likely acts upstream of the NICOTINE2 (NIC2) locus AP2/ERFs, to regulate nicotine biosynthesis in tobacco. Similar to the nicotine pathway genes, NtPP2C2b is highly expressed in roots and induced by jasmonate (JA). Overexpression of NtPP2C2b in transgenic hairy roots or stable transgenic tobacco plants repressed nicotine pathway gene expression and reduced nicotine accumulation. Additionally, transient overexpression of NtPP2C2b, together with the NtERF221, repressed transactivation of the quinolinate phosphoribosyltransferase (QPT) promoter in tobacco cells. We further demonstrated that the JA-responsive tobacco MAP Kinase 4 (NtMPK4) interacts with NtPP2C2b in yeast and plant cells. Conditional overexpression of NtMPK4 in tobacco hairy roots upregulated nicotine pathway gene expression and increased nicotine accumulation. Our findings suggest that a previously uncharacterized PP-PK module acts in concert to modulate alkaloid biosynthesis, highlighting the importance of posttranslational control in biosynthesis of plant specialized metabolites such as alkaloids.
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PMID:Protein-phosphatase NtPP2C2b and MAP-kinase NtMPK4 act in concert to modulate nicotine biosynthesis. 3325 46