Blockade of lysosomal calcium release due to lysosomal lipid accumulation has been shown to inhibit mTORC1 signaling. However, the mechanism by which lysosomal calcium regulates mTORC1 has remained undefined. Herein we report that proper lysosomal calcium release through the calcium channel TRPML1 is required for mTORC1 activation. TRPML1 depletion inhibits mTORC1 activity, while overexpression or pharmacologic activation of TRPML1 has the opposite effect. Lysosomal calcium activates mTORC1 by inducing association of calmodulin (CaM) with mTOR. Blocking the interaction between mTOR and CaM by antagonists of CaM significantly inhibits mTORC1 activity. Moreover, CaM is capable of stimulating the kinase activity of mTORC1 in a calcium-dependent manner . These results reveal that mTOR is a new type of CaM-dependent kinase, and TRPML1, lysosomal calcium and CaM play essential regulatory roles in the mTORC1 signaling pathway.
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http://dx.doi.org/10.7554/eLife.19360 | DOI Listing |
PLoS Genet
January 2025
Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 1st St. SW, Rochester, Minnesota 55905, United States of America.
Motor neuron diseases, such as amyotrophic lateral sclerosis (ALS) and progressive bulbar palsy, involve loss of muscle control resulting from death of motor neurons. Although the exact pathogenesis of these syndromes remains elusive, many are caused by genetically inherited mutations. Thus, it is valuable to identify additional genes that can impact motor neuron survival and function.
View Article and Find Full Text PDFNeuropathol Appl Neurobiol
February 2025
Department of Neurology, Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain.
Aims: Sarcoendoplasmic reticulum Ca-ATPase 2 (SERCA2), encoded by ATP2A2, is a key protein involved in intracellular Ca homeostasis. The SERCA2a isoform is predominantly expressed in cardiomyocytes and type I myofibres. Variants in this gene are related to Darier disease, an autosomal dominant dermatologic disorder, but have never been linked to myopathy.
View Article and Find Full Text PDFBone
January 2025
Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California at San Francisco, San Francisco, CA, United States of America.
This paper presents a review of the potential role of the endoplasmic reticulum/Golgi complex and intracellular vesicles in mediating events leading to or associated with vertebrate tissue mineralization. The possible importance of these organelles in this process is suggested by observations that calcium ions accumulate in the tubules and lacunae of the endoplasmic reticulum and Golgi. Similar levels of calcium ions (approaching millimolar) are present in vesicles derived from endosomes, lysosomes and autophagosomes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China.
Multidrug resistance (MDR) facilitates tumor recurrence and metastasis, which has become a main cause of chemotherapy failure in clinical. However, the current therapeutic effects against MDR remain unsatisfactory, mainly hampered by the rigid structure of drug-resistant cell membranes and the uncontrolled drug release. In this study, based on a sequential drug release strategy, we engineered a core-shell nanoparticle (DOX-M@CaP@ATV@HA) depleting cholesterol for reverse tumor MDR.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
Ferroptosis is a newly identified programmed cell death induced by iron-driven lipid peroxidation and implicated as a potential approach for tumor treatment. However, emerging evidence indicates that hepatocellular carcinoma (HCC) cells are generally resistant to ferroptosis and the underlying molecular mechanism is poorly understood. Here, our study confirms that S100 calcium binding protein P (S100P), which is significantly up-regulated in ferroptosis-resistant HCC cells, efficiently inhibits ferroptosis.
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