1
|
Sharma J, Mulherkar S, Chen UI, Xiong Y, Bajaj L, Cho BK, Goo YA, Leung HCE, Tolias KF, Sardiello M. Calpain activity is negatively regulated by a KCTD7-Cullin-3 complex via non-degradative ubiquitination. Cell Discov 2023; 9:32. [PMID: 36964131 PMCID: PMC10038992 DOI: 10.1038/s41421-023-00533-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 02/24/2023] [Indexed: 03/26/2023] Open
Abstract
Calpains are a class of non-lysosomal cysteine proteases that exert their regulatory functions via limited proteolysis of their substrates. Similar to the lysosomal and proteasomal systems, calpain dysregulation is implicated in the pathogenesis of neurodegenerative disease and cancer. Despite intensive efforts placed on the identification of mechanisms that regulate calpains, however, calpain protein modifications that regulate calpain activity are incompletely understood. Here we show that calpains are regulated by KCTD7, a cytosolic protein of previously uncharacterized function whose pathogenic mutations result in epilepsy, progressive ataxia, and severe neurocognitive deterioration. We show that KCTD7 works in complex with Cullin-3 and Rbx1 to execute atypical, non-degradative ubiquitination of calpains at specific sites (K398 of calpain 1, and K280 and K674 of calpain 2). Experiments based on single-lysine mutants of ubiquitin determined that KCTD7 mediates ubiquitination of calpain 1 via K6-, K27-, K29-, and K63-linked chains, whereas it uses K6-mediated ubiquitination to modify calpain 2. Loss of KCTD7-mediated ubiquitination of calpains led to calpain hyperactivation, aberrant cleavage of downstream targets, and caspase-3 activation. CRISPR/Cas9-mediated knockout of Kctd7 in mice phenotypically recapitulated human KCTD7 deficiency and resulted in calpain hyperactivation, behavioral impairments, and neurodegeneration. These phenotypes were largely prevented by pharmacological inhibition of calpains, thus demonstrating a major role of calpain dysregulation in KCTD7-associated disease. Finally, we determined that Cullin-3-KCTD7 mediates ubiquitination of all ubiquitous calpains. These results unveil a novel mechanism and potential target to restrain calpain activity in human disease and shed light on the molecular pathogenesis of KCTD7-associated disease.
Collapse
Affiliation(s)
- Jaiprakash Sharma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA.
| | - Shalaka Mulherkar
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Uan-I Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yan Xiong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA
| | - Lakshya Bajaj
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Byoung-Kyu Cho
- Mass Spectrometry Technology Access Center at the McDonnell Genome Institute, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Young Ah Goo
- Mass Spectrometry Technology Access Center at the McDonnell Genome Institute, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
- Department of Biochemistry and Molecular Biophysics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Hon-Chiu Eastwood Leung
- Departments of Medicine, Pediatrics, and Molecular and Cellular Biology, Dan Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Kimberley F Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Cell Biology, Baylor College of Medicine, Houston, TX, USA
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA.
| |
Collapse
|