Researchers from the John Innes Center and partners from the Chinese Academy of Sciences have identified a molecular switch that mediates differential cell growth and organ shape.
The growth regulator auxin promotes cell growth via a surface protein called Transmembrane Kinase 1 (TMK1). On the cell surface, TMK1 modulates cell wall properties that facilitate cell growth. But TMK1 also signals an opposite growth-retarding effect in the cell nucleus, where it suppresses cell growth by reducing auxin-mediated gene expression.
dr. Benguo Gu and his colleagues showed how TMK1 performs these seemingly opposite functions in different parts of the cell. This involves the cleavage of TMK1 protein at the cell surface and transfer of some of the spliced protein to the nucleus. Although this process is fairly common, it was difficult to identify the protein-cleaving proteins involved due to technical challenges.
The proteins involved are members of the DA1 family of peptidases. These enzymes cleave a variety of proteins involved in growth reactions and help shape organ growth. The demonstration of the splicing of the DA1 family from TMK1 shows how they modulate the flow of information from the cell surface to the nucleus to shape cell size and organ growth. Defining these processes makes an important contribution to our understanding of plant growth.
dr. Gu, a research assistant at the John Innes Center, says their “work showed that peptidases from the DA1 family act on hormone signal transduction, suggesting a common mechanism for transferring signal from plasma membrane to nucleus. The findings may provide a way to to improve the harvest.” seed emergence.”
“Modulation of receptor-like transmembrane kinase 1 nuclear localization by DA1 peptidases in Arabidopsis” is published in Proceedings of the National Academy of Sciences.
Newly discovered mechanism of plant hormone auxin is counterproductive
Benguo Gu et al, Modulation of receptor-like transmembrane kinase 1 nuclear localization by DA1 peptidases in Arabidopsis, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2205757119
Quote: How a Molecular Switch Shapes Plant Organ Growth (2022, October 3), retrieved October 3, 2022 from https://phys.org/news/2022-10-molecular-growth.html
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