Apoptosis, a form of programmed cell death that occurs under physiological as well as pathological conditions, is characterized by morphological and biochemical features. While the importance of caspases in apoptosis is established, several noncaspase proteases (Ca(2+)-dependent proteases) such as calpain may play a role in the execution of apoptosis. The calpain family consists of two major is...

Keratinocyte migration is critical to reepithelialization during wound repair. The motility response is promoted by growth factors, cytokines, and cytokines produced in the wound bed, including those that activate the epidermal growth factor (EGF) receptor. The Alu-Leu-Arg-negative CXC chemokine interferon-inducible protein 9 (IP-9; also known as CXCL11, I-TAC, beta-R1, and H-174) is produced b...

The calcium-sensing receptor (CaR) is a G protein-coupled, seven-transmembrane receptor and resides within caveolin-rich membrane domains in bovine parathyroid cells. The proenzyme of calpain 2 (m-calpain) is a heterodimeric calcium-dependent cysteine protease consisting of catalytic and regulatory subunits. The effects of calcium on the enzyme include activation, autolysis, and subunit dissoci...

The c-Myc transcription factor is commonly dysregulated in cancer. c-Myc also sensitizes cells to apoptosis induced by a variety of toxic events. c-Myc turnover is rapid and mediated by the proteasome and intracellular calpains. Therefore, c-Myc accumulation could contribute to cell death associated with protease inhibitors. We investigated the response of c-Myc-positive and c-Myc-negative rat ...

The role of Ca++ in cell death is controversial. Extracellular Ca++ influx and calpain activation occurred during the late phase of renal proximal tubule cell injury produced by the mitochondrial inhibitor antimycin A. Chelation of intracellular Ca++, extracellular Ca++, the calcium channel blocker nifedipine, calpain inhibitor 1 and the dissimilar calpain inhibitor PD150606 blocked antimycin A...

BACKGROUND Limb girdle muscular dystrophy (LGMD) type 2A is caused by mutations in the CAPN3 gene and complete lack of functional calpain 3 leads to the most severe muscle wasting. Calpain 3 is suggested to be involved in maturation of contractile elements after muscle degeneration. The aim of this study was to investigate how mutations in the four functional domains of calpain 3 affect muscle ...

BACKGROUND Calpains are intracellular, calcium-sensitive, neutral cysteine proteases that play crucial roles in many physiological and pathological processes. Calpain regulation is complex and activity is poorly correlated with calpain protein levels. Therefore a full understanding of calpain function requires robust methods for measuring activity. METHODS We describe and characterize a flow ...

Chemoattractants induce neutrophil polarization through localized polymerization of F-actin at the leading edge. The suppression of rear and lateral protrusions is required for efficient chemotaxis and involves the temporal and spatial segregation of signaling molecules. We have previously shown that the intracellular calcium-dependent protease calpain is required for cell migration and is invo...

BACKGROUND Basal-like and triple-negative breast tumours encompass an important clinical subgroup and biomarkers that can prognostically stratify these patients are required. MATERIALS AND METHODS We investigated two breast cancer tissue microarrays for the expression of calpain-1, calpain-2 and calpastatin using immunohistochemistry. The first microarray was comprised of invasive tumours fro...

Calpains are a family of intracellular cysteine proteases involved in various biological processes. Previously, the family was identified to have abnormal expression in several types of malignant tumor. Calpain 6 was less well known; however, it was recently identified to be involved in the carcinogenesis of certain types of malignant tumor. However, the expression of calpain 6 in head and neck...