The specific N-terminal sequence of rice phytocystatin OsCPI2 is the key domain for regulating its interaction with cysteine protease OsCysP7.
- 1College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, 650201, Yunnan, China.
- 2College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, 650201, Yunnan, China. [email protected].
- 3Rice research institute, Yunnan agricultural university, Kunming, 650201, Yunnan, China. [email protected].
Abstract
Cysteine proteases are proteolytic enzymes that are widely present in various plant tissues and organs and are involved in diverse cellular and physiological processes. Cystatin is a specific inhibitor of cysteine proteases. It restricts their activity by interacting with them within cells. Conserved cystatin inhibitor structures are typically located in the middle and C-terminal regions of the peptide. However, the mechanism by which cysteine proteases interact with specific cystatins remains unclear. In this study, the cold responsive rice cysteine protease OsCysP7 was used as bait to screen for interacting cystatins. Of the 12 rice cystatins tested, none could interact with the precursor of OsCysP7, which bears the self-inhibitory domain. Only OsCPI2 was found to interact with the mature OsCysP7 via yeast two-hybrid screening. This interaction was further confirmed by a bimolecular fluorescence complementation (BiFC) test. Analysis of the interaction domains showed that only the N-terminal sequence of OsCPI2 could interact with mature OsCysP7. A fragment comprising the first 57 amino acids in the N-terminal region was sufficient for interaction with mature OsCysP7. Although the C-terminus of OsCPI2 comprises two conserved inhibitory domains, these domains alone were insufficient for interaction with mature OsCysP7. Further experiments with variants of OsCPI2 revealed that the residue at position 57 was crucial for the specific interaction between the two proteins. This suggests that the N-terminal region of OsCPI2 is the key domain responsible for determining its interaction with mature OsCysP7.
Related
- C-terminal domain of SARS CoV 2 nucleocapsid protein binds transcriptional regulatory sequence RNA with high affinity and forms higher-order assemblies
- Association Between Changes in Serum N-Terminal Pro B-Type Natriuretic Peptide Levels and All-Cause and Cause-Specific Mortality ― The Hisayama Study ―
- Drug-drug interaction between ticagrelor and fazamorexant: pharmacokinetic alterations in healthy subjects from a phase I, open-label, fixed-sequence study
- Sequence-based variant-effect predictions reveal trait-specific regulatory-layer profiles of complex-trait heritability
- Psychopathology-AI-interaction (PAII) framework: Disorder-specific dynamics in conversational AI
BibTeX
@article{zhang2026specific,
title = {{The specific N-terminal sequence of rice phytocystatin OsCPI2 is the key domain for regulating its interaction with cysteine protease OsCysP7.}},
author = {Yue Zhang and Yingxue Sun and Mingbo Li and Heling Bai and Jin Xu},
journal = {BMC plant biology},
year = {2026},
month = aug,
doi = {10.1186/s12870-026-09658-5},
url = {https://europepmc.org/article/MED/42958023},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - The specific N-terminal sequence of rice phytocystatin OsCPI2 is the key domain for regulating its interaction with cysteine protease OsCysP7.
AU - Yue Zhang
AU - Yingxue Sun
AU - Mingbo Li
AU - Heling Bai
AU - Jin Xu
PY - 2026
DA - 2026/08/01
JO - BMC plant biology
DO - 10.1186/s12870-026-09658-5
UR - https://europepmc.org/article/MED/42958023
AB - Cysteine proteases are proteolytic enzymes that are widely present in various plant tissues and organs and are involved in diverse cellular and physiological processes. Cystatin is a specific inhibitor of cysteine proteases. It restricts their activity by interacting with them within cells. Conserved cystatin inhibitor structures are typically located in the middle and C-terminal regions of the peptide. However, the mechanism by which cysteine proteases interact with specific cystatins remains unclear. In this study, the cold responsive rice cysteine protease OsCysP7 was used as bait to screen for interacting cystatins. Of the 12 rice cystatins tested, none could interact with the precursor of OsCysP7, which bears the self-inhibitory domain. Only OsCPI2 was found to interact with the mature OsCysP7 via yeast two-hybrid screening. This interaction was further confirmed by a bimolecular fluorescence complementation (BiFC) test. Analysis of the interaction domains showed that only the N-terminal sequence of OsCPI2 could interact with mature OsCysP7. A fragment comprising the first 57 amino acids in the N-terminal region was sufficient for interaction with mature OsCysP7. Although the C-terminus of OsCPI2 comprises two conserved inhibitory domains, these domains alone were insufficient for interaction with mature OsCysP7. Further experiments with variants of OsCPI2 revealed that the residue at position 57 was crucial for the specific interaction between the two proteins. This suggests that the N-terminal region of OsCPI2 is the key domain responsible for determining its interaction with mature OsCysP7.
SN - 1471-2229
ER -