Phosphorylation by AtMPK6 is required for the biological function of AtMYB41 in Arabidopsis

• Published in: Biochemical and biophysical research communications Vol. 422; no. 1; pp. 181 - 186
• Main Authors: Hoang, My Hanh Thi, Nguyen, Xuan Canh, Lee, Kyunghee, Kwon, Young Sang, Pham, Huyen Trang Thi, Park, Hyeong Cheol, Yun, Dae-Jin, Lim, Chae Oh, Chung, Woo Sik
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25-05-2012
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; MAP kinase; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Salt; Salt-Tolerance; Serine - genetics; Serine - metabolism; Transcription factor; Transcription Factors - genetics; Transcription Factors - metabolism; Salt; MAP kinase; Phosphorylation; Transcription factor; Arabidopsis
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.04.137

Ser251 in MYB41 was identified as the site phosphorylated by MPK6. Transgenic plants over-expressing MYB41WT showed enhanced salt tolerance, whereas transgenic plants over-expressing MYB41S251A showed decreased salt tolerance during seed germination and initial root growth. [Display omitted]
► MYB41 transcription factor was identified as a substrate of MPK6 in Arabidopsis. ► The phosphorylation of MYB41 by MPK6 enhanced its DNA binding affinity. ► Ser251 residue in MYB41 was identified as the site phosphorylated by MPK6. ► Transgenic plants over-expressing MYB41WT showed increased salt tolerance. ► Transgenic plants over-expressing MYB41S251A showed decreased salt tolerance.
Mitogen-activated protein kinases (MPKs) are involved in a number of signaling pathways that control plant development and stress tolerance via the phosphorylation of target molecules. However, so far only a limited number of target molecules have been identified. Here, we provide evidence that MYB41 represents a new target of MPK6. MYB41 interacts with MPK6 not only in vitro but also in planta. MYB41 was phosphorylated by recombinant MPK6 as well as by plant MPK6. Ser251 in MYB41 was identified as the site phosphorylated by MPK6. The phosphorylation of MYB41 by MPK6 enhanced its DNA binding to the promoter of a LTP gene. Interestingly, transgenic plants over-expressing MYB41WT showed enhanced salt tolerance, whereas transgenic plants over-expressing MYB41S251A showed decreased salt tolerance during seed germination and initial root growth. These results indicate that the phosphorylation of MYB41 by MPK6 is required for the biological function of MYB41 in salt tolerance.