Ojha Madhusmita, Verma Deepanjali, Chakraborty Nibedita, Pal Abhideep, Bhagat Prakash Kumar, Singh Anshuman, Verma Neetu, Sinha Alok Krishna, Chattopadhyay Sudip
Department of Biotechnology, National Institute of Technology, Durgapur 713209, India.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.
iScience. 2023 Jan 25;26(2):106049. doi: 10.1016/j.isci.2023.106049. eCollection 2023 Feb 17.
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 double mutant analysis shows that MYC2 works downstream to MKKK20 in the regulation of photomorphogenic growth. MYC2 directly binds to the promoter of 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 expression. Further, the protein phosphorylation studies demonstrate that MKKK20 works as the upstream kinase of MKK3-MPK6-MYC2 module in photomorphogenesis.
丝裂原活化蛋白激酶（MAPK）级联反应参与真核生物中的多种信号转导过程。在此，我们报道了丝裂原活化蛋白激酶激酶激酶20（MKKK20）在光信号转导途径中的机制功能。我们表明，MKKK20在不同波长的光下作为光形态建成生长的负调节因子。MKKK20不仅调节光信号通路调节基因的表达，还受到相同通路基因的调节。双突变分析表明，在光形态建成生长的调节中，MYC2在MKKK20的下游起作用。MYC2直接结合到的启动子上以调节其表达。蛋白质-蛋白质相互作用研究表明，MKKK20与MYC2发生物理相互作用，这种相互作用可能抑制MYC2介导的表达促进作用。此外，蛋白质磷酸化研究表明，MKKK20在光形态建成中作为MKK3-MPK6-MYC2模块的上游激酶发挥作用。
