Identification of Calcium-Sensing Receptor (CAS) as a Phytaspase Interactor: Implications for the CAS Trafficking Pathway
- 1Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
- 2Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia
- 3Institute of Biomedical Chemistry, Moscow 119121, Russia
Abstract
Proteolytic enzymes play important and diverse roles in regulating protein homeostasis in living cells. Phytaspase, a member of the plant subtilisin-like protease family possessing a ‘caspase-like’ selectivity and specificity of hydrolysis of its targets, is a cell death-related protease. Phytaspase displays a peculiar trafficking pattern and is involved in the execution of plant cell death induced by biotic and abiotic stresses. To elucidate the molecular mechanisms of phytaspase functioning, a search for Nicotiana tabacum phytaspase (NtPhyt)-interacting proteins was performed using the BioID approach. This search identified the calcium-sensing receptor (CAS) protein as a candidate NtPhyt interactor. Direct interaction of NtPhyt with N. tabacum CAS (NtCAS) was corroborated by an in vitro analysis utilizing the purified proteins. Furthermore, NtPhyt was shown to introduce five cleavages in the CAS molecule in vitro. For NtCAS-EGFP produced in N. benthamiana leaves, dual localization to chloroplasts and the cell periphery, including the plasma membrane, was observed, whereas NtPhyt proteolytic activity was undetectable in the chloroplasts. A CAS precursor protein apparently preserving the chloroplast transit peptide was found to accumulate upon a light-to-dark transition and to disappear in the presence of elevated levels of NtPhyt. A requirement for CAS for stress-induced retrograde transport of NtPhyt was uncovered, and partial co-localization of CAS with NtPhyt was observed in cells subjected to oxidative stress. Our results are consistent with the model according to which CAS transiently localizes to the plasma membrane as an intermediate location on its way to its final destination, the chloroplasts, and interacts with NtPhyt at this stage.
Related
- Regulation of calcium-sensing-receptor trafficking and cell-surface expression by GPCRs and RAMPs
- ALOX15 links lipid metabolism to receptor trafficking in platelet activation
- AP2σ Mutations Impair Calcium-Sensing Receptor Trafficking and Signaling, and Show an Endosomal Pathway to Spatially Direct G-Protein Selectivity
- A single domain intrabody biases the follicle-stimulating hormone receptor subcellular trafficking
- Beyond Receptor-Proximal Uncoupling: EGFR-PKC Signaling and Arrestin Deubiquitination-Coupled Nuclear Trafficking in GPCR Signaling Regulation
BibTeX
@article{litvinova2026identification,
title = {{Identification of Calcium-Sensing Receptor (CAS) as a Phytaspase Interactor: Implications for the CAS Trafficking Pathway}},
author = {Anastasia V. Litvinova and Artemii A. Pigidanov and Tatevik A. Torosian and Victor G. Zgoda and Marina V. Serebryakova and Irina E. Kovaleva and Mahir D. Mamedov and Sergei A. Golyshev and Grigoriy G. Safronov and Nina V. Chichkova and Andrey B. Vartapetian},
journal = {International Journal of Molecular Sciences},
year = {2026},
month = oct,
doi = {10.3390/ijms27209202},
url = {https://www.mdpi.com/1422-0067/27/20/9202},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Identification of Calcium-Sensing Receptor (CAS) as a Phytaspase Interactor: Implications for the CAS Trafficking Pathway
AU - Anastasia V. Litvinova
AU - Artemii A. Pigidanov
AU - Tatevik A. Torosian
AU - Victor G. Zgoda
AU - Marina V. Serebryakova
AU - Irina E. Kovaleva
AU - Mahir D. Mamedov
AU - Sergei A. Golyshev
AU - Grigoriy G. Safronov
AU - Nina V. Chichkova
AU - Andrey B. Vartapetian
PY - 2026
DA - 2026/10/01
JO - International Journal of Molecular Sciences
DO - 10.3390/ijms27209202
UR - https://www.mdpi.com/1422-0067/27/20/9202
AB - Proteolytic enzymes play important and diverse roles in regulating protein homeostasis in living cells. Phytaspase, a member of the plant subtilisin-like protease family possessing a ‘caspase-like’ selectivity and specificity of hydrolysis of its targets, is a cell death-related protease. Phytaspase displays a peculiar trafficking pattern and is involved in the execution of plant cell death induced by biotic and abiotic stresses. To elucidate the molecular mechanisms of phytaspase functioning, a search for Nicotiana tabacum phytaspase (NtPhyt)-interacting proteins was performed using the BioID approach. This search identified the calcium-sensing receptor (CAS) protein as a candidate NtPhyt interactor. Direct interaction of NtPhyt with N. tabacum CAS (NtCAS) was corroborated by an in vitro analysis utilizing the purified proteins. Furthermore, NtPhyt was shown to introduce five cleavages in the CAS molecule in vitro. For NtCAS-EGFP produced in N. benthamiana leaves, dual localization to chloroplasts and the cell periphery, including the plasma membrane, was observed, whereas NtPhyt proteolytic activity was undetectable in the chloroplasts. A CAS precursor protein apparently preserving the chloroplast transit peptide was found to accumulate upon a light-to-dark transition and to disappear in the presence of elevated levels of NtPhyt. A requirement for CAS for stress-induced retrograde transport of NtPhyt was uncovered, and partial co-localization of CAS with NtPhyt was observed in cells subjected to oxidative stress. Our results are consistent with the model according to which CAS transiently localizes to the plasma membrane as an intermediate location on its way to its final destination, the chloroplasts, and interacts with NtPhyt at this stage.
SN - 1422-0067
ER -