PXD031321

PXD031321 is an original dataset announced via ProteomeXchange.

Title	Calpain Cleavage of Junctophilin-2 generates a Spectrum of Calcium-dependent Cleavage Products and DNA-rich NT1-Fragment Domains in Cardiomyocytes
Description	Calpains are calcium (Ca2+) activated neutral proteases that are involved in several essential signaling pathways. One Calpain-specific proteolytic target is Junctophilin-2 (JP2), an important structural protein of Ca2+ release units required for the excitation-contraction coupling in cardiomyocytes. While downregulation of JP2 by Calpain cleavage in mouse models of heart failure has been reported previously, the precise molecular identity of the Calpain cleavage sites and the (patho-) physiological roles of the JP2 proteolytic products remain controversial. We systematically analyzed the JP2 cleavage fragments as function of Calpain-1 versus Calpain-2 proteolytic activities, revealing that both Calpain isoforms preferentially cleave mouse JP2 at R565 but subsequently also at three additional secondary Calpain cleavage sites. We identified the Calpain-specific primary cleavage products not only in mouse but also in human iPSC-derived cardiomyocytes (hiPSC-CMs). Knockout of RyR2 in hiPSC-CMs destabilized JP2 resulting in an increase of the Calpain-specifc cleavage fragments. The primary N-terminal cleavage product (NT1) accumulated in the nucleus of mouse and human cardiomyocytes in a Ca2+ dependent manner, closely associated with DNA-rich chromosomal regions, where NT1 is proposed to function as a cardioprotective transcriptional regulator in heart failure. Taken together, our data suggest that stabilizing NT1 by preventing secondary cleavage events by Calpain and other proteases could be an important therapeutic target for future studies.
HostingRepository	PRIDE
AnnounceDate	2022-08-12
AnnouncementXML	Submission_2022-08-12_00:25:57.558.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Christof Lenz
SpeciesList	scientific name: Mus musculus (Mouse); NCBI TaxID: 10090;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive

Revision	Datetime	Status	ChangeLog Entry
0	2022-01-30 10:48:06	ID requested
⏵ 1	2022-08-12 00:25:58	announced

Weninger G, Pochechueva T, El Chami D, Luo X, Kohl T, Brandenburg S, Urlaub H, Guan K, Lenz C, Lehnart SE, -fragment domains in cardiomyocytes. Sci Rep, 12(1):10387(2022) [pubmed]

submitter keyword: Calcium, Calpain, Cardiomyocyte, Junctophilin, Ryanodine

Christof Lenz
contact affiliation	Core Facility Proteomics, Department of Clinical Chemistry, University Medical Center Göttingen, Germany
contact email	christof.lenz@med.uni-goettingen.de
lab head
Christof Lenz
contact affiliation	Max Planck Institute for Biophysical Chemistry
contact email	christof.lenz@mpibpc.mpg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD031321
     1. Label: PRIDE project
     2. Name: Calpain Cleavage of Junctophilin-2 generates a Spectrum of Calcium-dependent Cleavage Products and DNA-rich NT1-Fragment Domains in Cardiomyocytes