Regulation of Three Key Kinases of Brassinosteroid Signaling Pathway

• Published in: International journal of molecular sciences Vol. 21; no. 12; p. 4340
• Main Authors: Mao, Juan, Li, Jianming
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18-06-2020; MDPI
• Subjects: Binding sites; Biology; Brassinosteroids; Brassinosteroids - metabolism; Cell division; Cell surface; Gene expression; Gene Expression Regulation, Plant; GSK3-like kinases; Hormones; Kinases; Ligands; Metabolic Networks and Pathways; Phosphorylation; Plant Proteins - genetics; Plants - enzymology; Plants - genetics; Protein Kinases - genetics; protein phosphatases; Proteins; receptor-like kinases; Review; Senescence; Signal processing; Signal transduction; somatic embryogenesis receptor-like kinases; Transcription factors; GSK3-like kinases; receptor-like kinases; brassinosteroids; somatic embryogenesis receptor-like kinases; protein phosphatases
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21124340

Brassinosteroids (BRs) are important plant growth hormones that regulate a wide range of plant growth and developmental processes. The BR signals are perceived by two cell surface-localized receptor kinases, Brassinosteroid-Insensitive1 (BRI1) and BRI1-Associated receptor Kinase (BAK1), and reach the nucleus through two master transcription factors, bri1-EMS suppressor1 (BES1) and Brassinazole-resistant1 (BZR1). The intracellular transmission of the BR signals from BRI1/BAK1 to BES1/BZR1 is inhibited by a constitutively active kinase Brassinosteroid-Insensitive2 (BIN2) that phosphorylates and negatively regulates BES1/BZR1. Since their initial discoveries, further studies have revealed a plethora of biochemical and cellular mechanisms that regulate their protein abundance, subcellular localizations, and signaling activities. In this review, we provide a critical analysis of the current literature concerning activation, inactivation, and other regulatory mechanisms of three key kinases of the BR signaling cascade, BRI1, BAK1, and BIN2, and discuss some unresolved controversies and outstanding questions that require further investigation.