Isolation of ATMEKK1 (a MAP kinase kinase kinase): Interacting proteins and analysis of a MAP kinase cascade in Arabidopsis

Kazuya Ichimura, Tsuyoshi Mizoguchi, Kenji Irie, Peter Morris, Jérôme Giraudat, Kunihiro Matsumoto, Kazuo Shinozaki

    Research output: Contribution to journalArticle

    140 Citations (Scopus)

    Abstract

    In plants, a number of MAP kinase (MAPK), MAPK kinase (MAPKK), and MAPKK kinase (MAPKKK) homologues have been reported. However, there have been no reports of protein-protein interactions between these kinases or molecular analysis of MAPK cascades in higher plants. To analyze a possible MAPK cascade in Arabidopsis thaliana, we took two molecular approaches. One is the two-hybrid screening of ATMEKK1 (a MAPKKK)-interacting proteins; the other is an analysis of physical and functional interactions among isolated MAPK, MAPKK, and MAPKKK homologues from Arabidopsis. In two-hybrid screening using ATMEKK1 as bait, we isolated a novel MAPKK homologue, ATMKK2, a MAPK homologue, ATMPK4, and an unknown protein. ATMKK2 has high sequence similarity with MEK1 (a MAPKK) in Arabidopsis. Based on yeast two-hybrid analysis, we detected protein-protein interactions between ATMEKK1 and ATMKK2/MEK1 (MAPKKs), between ATMKK2/ MEK1 and ATMPK4 (a MAPK), and between ATMPK4 and ATMEKK1. ATMPK4 and ATMKK2/MEK1 interacted with two distinct regions of ATMEKK1, the N-terminal regulatory domain and the C-terminal kinase domain, respectively. Coexpression of ATMEKK1 increased the ability of two closely related MAPKKs, ATMKK2 and MEK1, to complement a growth defect of the yeast pbs2 mutant. Coexpression of ATMPK4 and MEK1 complemented a growth defect of the yeast mpk1 and bck1 mutants. By contrast, other combinations of MAPKs and MAPKKs did not suppress these yeast mutations. These results suggest that ATMEKK1, ATMKK2/MEK1, and ATMPK4 may constitute a MAP kinase cascade.

    Original languageEnglish
    Pages (from-to)532-543
    Number of pages12
    JournalBiochemical and Biophysical Research Communications
    Volume253
    Issue number2
    DOIs
    Publication statusPublished - 18 Dec 1998

    Fingerprint Dive into the research topics of 'Isolation of ATMEKK1 (a MAP kinase kinase kinase): Interacting proteins and analysis of a MAP kinase cascade in Arabidopsis'. Together they form a unique fingerprint.

  • Cite this