Single cystathionine β-synthase domain-containing proteins modulate development by regulating the thioredoxin system in Arabidopsis

Kyoung Shin Yoo, Sung Han Ok, Byung Cheon Jeong, Kwang Wook Jung, Mei Hua Cui, Sujin Hyoung, Myeong Ryeol Lee, Hyun Kyu Song, Jeong Sheop Shin

Research output: Contribution to journalArticle

45 Citations (Scopus)


Plant thioredoxins (Trxs) participate in two redox systems found in different cellular compartments: the NADP-Trx system (NTS) in the cytosol and mitochondria and the ferredoxin-Trx system (FTS) in the chloroplast, where they function as redox regulators by regulating the activity of various target enzymes. The identities of the master regulators that maintain cellular homeostasis and modulate timed development through redox regulating systems have remained completely unknown. Here, we show that proteins consisting of a single cystathionine β-synthase (CBS) domain pair stabilize cellular redox homeostasis and modulate plant development via regulation of Trx systems by sensing changes in adenosine-containing ligands. We identified two CBS domain-containing proteins in Arabidopsis thaliana, CBSX1 and CBSX2, which are localized to the chloroplast, where they activate all four Trxs in the FTS. CBSX3 was found to regulate mitochondrial Trx members in the NTS. CBSX1 directly regulates Trxs and thereby controls H 2O 2 levels and regulates lignin polymerization in the anther endothecium. It also affects plant growth by regulating Calvin cycle enzymes, such as malate dehydrogenase, via homeostatic regulation of Trxs. Based on our findings, we suggest that the CBSX proteins (or a CBS pair) are ubiquitous redox regulators that regulate Trxs in the FTS and NTS to modulate development and maintain homeostasis under conditions that are threatening to the cell.

Original languageEnglish
Pages (from-to)3577-3594
Number of pages18
JournalPlant Cell
Issue number10
Publication statusPublished - 2011 Dec 1


ASJC Scopus subject areas

  • Plant Science
  • Cell Biology

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