The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1
Type 1 protein phosphatases (PP1s) are crucial in various plant cellular processes. Their function is controlled by regulators known as PP1-interacting proteins (PIPs), often intrinsically disordered, such as Inhibitor 2 (I2), conserved across kingdoms. The durum wheat <i>Td</i>RL1 acts...
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2025-04-01
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| author | Fatma Amor Mariem Bradai Ikram Zaidi Vitor Amorim-Silva Nabil Miled Moez Hanin Chantal Ebel |
| author_facet | Fatma Amor Mariem Bradai Ikram Zaidi Vitor Amorim-Silva Nabil Miled Moez Hanin Chantal Ebel |
| author_sort | Fatma Amor |
| collection | DOAJ |
| description | Type 1 protein phosphatases (PP1s) are crucial in various plant cellular processes. Their function is controlled by regulators known as PP1-interacting proteins (PIPs), often intrinsically disordered, such as Inhibitor 2 (I2), conserved across kingdoms. The durum wheat <i>Td</i>RL1 acts as a positive regulator of plant stress tolerance, presumably by inhibiting PP1 activity. In this work, co-immunoprecipitation and bimolecular fluorescence complementation (BiFC) assays demonstrate that the durum wheat <i>Td</i>PP1 interacts with both <i>Td</i>RL1 and <i>At</i>-I2 in vivo. YFP fluorescence restored after <i>Td</i>RL1-<i>Td</i>PP1 interaction decorated specifically the microtubular network of the tobacco co-infiltrated cells. In vitro phosphatase assays revealed that <i>Td</i>RL1 inhibited the activity of wild-type <i>Td</i>PP1 and two mutant forms (T243M and H135A) in a concentration-dependent manner, showing a novel and potent inhibition mechanism. Structural modeling of the <i>Td</i>PP1-inhibitor complexes suggested that both <i>At</i>-I2 and <i>Td</i>RL1 bind to <i>Td</i>PP1 by wrapping their flexible C-terminal tails around it, blocking access to the active site. Remarkably, the model showed that <i>Td</i>RL1 differs from <i>At</i>-I2 in its interaction with <i>Td</i>PP1 by trapping the phosphatase with its N-terminal tail. These findings provide important insights into the regulatory mechanisms governing the activity of PP1s in plants and highlight the potential for targeted inhibition to modulate plant stress responses. |
| format | Article |
| id | doaj-art-e3fb8f60271e48fa94c711534fd247ff |
| institution | Kabale University |
| issn | 2218-273X |
| language | English |
| publishDate | 2025-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj-art-e3fb8f60271e48fa94c711534fd247ff2025-08-20T03:47:48ZengMDPI AGBiomolecules2218-273X2025-04-0115563110.3390/biom15050631The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1Fatma Amor0Mariem Bradai1Ikram Zaidi2Vitor Amorim-Silva3Nabil Miled4Moez Hanin5Chantal Ebel6Functional Genomics and Plant Physiology Laboratory, Institute of Biotechnology, University of Sfax, P.O. Box 1175, Sfax 3038, TunisiaFunctional Genomics and Plant Physiology Laboratory, Institute of Biotechnology, University of Sfax, P.O. Box 1175, Sfax 3038, TunisiaBiotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, P.O. Box 1177, Road Sidi Mansour km 6, Sfax 3018, TunisiaÁrea de Mejora y Fisiología de Plantas, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, 29010 Málaga, SpainFunctional Genomics and Plant Physiology Laboratory, Institute of Biotechnology, University of Sfax, P.O. Box 1175, Sfax 3038, TunisiaFunctional Genomics and Plant Physiology Laboratory, Institute of Biotechnology, University of Sfax, P.O. Box 1175, Sfax 3038, TunisiaFunctional Genomics and Plant Physiology Laboratory, Institute of Biotechnology, University of Sfax, P.O. Box 1175, Sfax 3038, TunisiaType 1 protein phosphatases (PP1s) are crucial in various plant cellular processes. Their function is controlled by regulators known as PP1-interacting proteins (PIPs), often intrinsically disordered, such as Inhibitor 2 (I2), conserved across kingdoms. The durum wheat <i>Td</i>RL1 acts as a positive regulator of plant stress tolerance, presumably by inhibiting PP1 activity. In this work, co-immunoprecipitation and bimolecular fluorescence complementation (BiFC) assays demonstrate that the durum wheat <i>Td</i>PP1 interacts with both <i>Td</i>RL1 and <i>At</i>-I2 in vivo. YFP fluorescence restored after <i>Td</i>RL1-<i>Td</i>PP1 interaction decorated specifically the microtubular network of the tobacco co-infiltrated cells. In vitro phosphatase assays revealed that <i>Td</i>RL1 inhibited the activity of wild-type <i>Td</i>PP1 and two mutant forms (T243M and H135A) in a concentration-dependent manner, showing a novel and potent inhibition mechanism. Structural modeling of the <i>Td</i>PP1-inhibitor complexes suggested that both <i>At</i>-I2 and <i>Td</i>RL1 bind to <i>Td</i>PP1 by wrapping their flexible C-terminal tails around it, blocking access to the active site. Remarkably, the model showed that <i>Td</i>RL1 differs from <i>At</i>-I2 in its interaction with <i>Td</i>PP1 by trapping the phosphatase with its N-terminal tail. These findings provide important insights into the regulatory mechanisms governing the activity of PP1s in plants and highlight the potential for targeted inhibition to modulate plant stress responses.https://www.mdpi.com/2218-273X/15/5/631PP1<i>Td</i>RL1phosphatase activityPP1-interacting proteinsthree-dimensional structure prediction |
| spellingShingle | Fatma Amor Mariem Bradai Ikram Zaidi Vitor Amorim-Silva Nabil Miled Moez Hanin Chantal Ebel The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 Biomolecules PP1 <i>Td</i>RL1 phosphatase activity PP1-interacting proteins three-dimensional structure prediction |
| title | The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 |
| title_full | The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 |
| title_fullStr | The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 |
| title_full_unstemmed | The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 |
| title_short | The Wheat Intrinsically Disordered Protein <i>Td</i>RL1 Negatively Regulates the Type One Protein Phosphatase <i>Td</i>PP1 |
| title_sort | wheat intrinsically disordered protein i td i rl1 negatively regulates the type one protein phosphatase i td i pp1 |
| topic | PP1 <i>Td</i>RL1 phosphatase activity PP1-interacting proteins three-dimensional structure prediction |
| url | https://www.mdpi.com/2218-273X/15/5/631 |
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