Arabidopsis KIN gamma subunit 1 has a potential to regulate activity of sucrose nonfermenting 1-related protein kinase 2s (SnRK2s) in vitro

M Punkkinen, Konstantin Denessiouk, H Fujii

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)


Plants must precisely regulate their signalling pathways to respond to environmental changes promptly. Sucrose non fermenting1 (SNF1)-related protein kinases (SnRK) 2 are essential kinases in abiotic stress responses, including responses to abscisic acid. Although homologs of SnRKs in yeast require a gamma-subunit for full activation, it has been unclear whether SnRK2s in higher plants are affected by gamma-subunits. In this report, we aimed to show the effect of Arabidopsis KIN gamma subunit 1 (KING1), which is a potential gamma-subunit, on the activity of SnRK2. A recombinant KING1 bound to SnRK2.6 and functionally inhibited its activity in vitro. On the other hand, KING1 facilitated the activity of SnRK2.2. Structural models suggest that significant structural changes occurred as a result of KING1 binding to the C-terminal tail of SnRK2s. Since KING1 inhibited the kinase activity of a chimeric protein consisting of the N-terminal domain of SnRK2.6 and the C-terminal domain of SnRK2.2, regulation by KING1 was determined by the N-terminal domain of SnRK2s. Together, these results show that KING1 can mediate activity of SnRK2s in vitro.
Original languageUndefined/Unknown
Pages (from-to)54–58
Number of pages5
JournalBiologia Plantarum
Publication statusPublished - 2019
MoE publication typeA1 Journal article-refereed


  • activation of kinase
  • structural models
  • abscisic acid

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