MKKK20 works as an upstream triple-kinase of MKK3-MPK6-MYC2 module in Arabidopsis seedling development

• Published in: iScience 2023-02, Vol.26 (2), p.106049-106049, Article 106049
• Main Authors: Ojha, Madhusmita, Verma, Deepanjali, Chakraborty, Nibedita, Pal, Abhideep, Bhagat, Prakash Kumar, Singh, Anshuman, Verma, Neetu, Sinha, Alok Krishna, Chattopadhyay, Sudip
• Format: Article
• Language: English
• Subjects: Molecular biology; Plant development; Plant physiology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2023.106049

The mitogen-activated protein kinase (MAPK) cascade is involved in several signal transduction processes in eukaryotes. Here, we report a mechanistic function of MAP kinase kinase kinase 20 (MKKK20) in light signal transduction pathways. We show that MKKK20 acts as a negative regulator of photomorphogenic growth at various wavelengths of light. MKKK20 not only regulates the expression of light signaling pathway regulatory genes but also gets regulated by the same pathway genes. The atmyc2 mkkk20 double mutant analysis shows that MYC2 works downstream to MKKK20 in the regulation of photomorphogenic growth. MYC2 directly binds to the promoter of MKKK20 to modulate its expression. The protein-protein interaction study indicates that MKKK20 physically interacts with MYC2, and this interaction likely suppresses the MYC2-mediated promotion of MKKK20 expression. Further, the protein phosphorylation studies demonstrate that MKKK20 works as the upstream kinase of MKK3-MPK6-MYC2 module in photomorphogenesis. [Display omitted] •MKKK20 is the upstream kinase of MKK3-MPK6-MYC2 module in photomorphogenesis•MYC2-mediated promotion of MKKK20 expression is nullified by MYC2-MKKK20 complex•MKKK20 and MYC2 work in a feedback loop mechanism in light signaling pathway•MYC2 regulates MKKK20-MKK3-MPK6 cascade in Arabidopsis seedling development Molecular biology; Plant physiology; Plant development