NCBI Accession #
NP_175577.1
NCBI GenBank Nucleotide #
NM_104044.3
NCBI Official Full Name
mitogen-activated protein kinase kinase 4
NCBI Official Symbol
MKK4
NCBI Official Synonym Symbols
ARABIDOPSIS THALIANA MITOGEN-ACTIVATED PROTEIN KINASE KINASE 4; ATMEK4; ATMKK4; F19C24.26; F19C24_26; MAP KINASE KINASE 4; mitogen-activated protein kinase kinase 4
NCBI Protein Information
mitogen-activated protein kinase kinase 4
NCBI Summary
Encodes a mitogen-activated map kinase kinase (there are nine in Arabidopsis) involved in innate immunity. This protein activates MPK3/MPK6 and early-defense genes redundantly with MKK5. In plants with both MKK5 and MKK6 levels reduced by RNAi plants, floral organs do not abscise suggestion a role for both proteins in mediating floral organ abscission.
UniProt Synonym Gene Names
AtMKK4; MAP kinase kinase 4
UniProt Protein Name
Mitogen-activated protein kinase kinase 4
UniProt Primary Accession #
O80397
UniProt Related Accession #
O80397
UniProt Comments
Involved in the second phase of hydrogen peroxide generation during hypersensitive response-like cell death. Involved in the innate immune MAP kinase signaling cascade (MEKK1, MKK4/MKK5 and MPK3/MPK6) downstream of bacterial flagellin receptor FLS2. Activates by phosphorylation the downstream MPK3 and MPK6. YDA-MKK4/MKK5-MPK3/MPK6 module regulates stomatal cell fate before the guard mother cell (GMC) is specified. This MAPK cascade also functions downstream of the ER receptor in regulating coordinated local cell proliferation, which shapes the morphology of plant organs. MKK4 and MKK5 participate in the regulation of floral organ abscission. Mediates osmotic-stress response via its regulation of MPK3 activity. Target of the Pseudomonas syringae type III effector HopF2.