The switch of human melanoma cell phenotype from non to highly tumorigenic and metastatic is triggered by the increase of procathepsin L secretion, which modifies the tumour microenvironment. The aim of the present study was to identify components involved in the regulation of procathepsin L secretion in melanoma cells. We focused on Rab family members, i.e. Rab3A, Rab4A, Rab4B, Rab5A, Rab8A, Rab11A, Rab27A and Rab33A, which are involved in distinct regulatory pathways. From analysis of mRNA and protein expression of these Rab components and their knockdown by specific siRNAs (small interfering RNAs) it emerged that Rab4A protein is involved in the regulation of procathepsin L secretion. This result was strengthened as procathepsin L secretion was either inhibited by expression of a Rab4A dominant-negative mutant or increased by overexpression of the wild-type Rab4A. Rab4A regulation: (i) discriminates between procathepsin L secretion and expression of intracellular cathepsin L forms; (ii) did not modify other Rab proteins and GAPDH (glyceraldehyde-3-phosphate dehydrogenase) expression, or IL-8 (interleukin-8) and MMP-2 (matrix metalloproteinase-2) secretion; and (iii) was still efficient during unglycosylated procathepsin L secretion. Thus down- or up-regulation of Rab4A expression or Rab4A function triggered inhibition or increase of procathepsin L secretion respectively. Furthermore, Rab4A regulation, by modifying procathepsin L secretion, switches the tumorigenic phenotype of human melanoma cells in nude mice.
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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 PDFOpen Vet J
November 2024
Parasitology Department, Faculty of Veterinary Medicine, Universitas Syiah Kuala, Banda Aceh, Indonesia.
Background: Cathepsin-L (FhCL) is a group of enzymes that most flukes express and secreted significantly in parasite-host interactions. Researches are focusing on antigens released by as one of the keys to understanding immunologic pathways in parasite infection and targets for anthelmintics. Efforts to suppress FhCL function through vaccination or therapy using anthelmintic drugs are key factors in controlling field-level trematode infections.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
December 2024
Institute of Biochemistry, Department of Biotechnology and Enzyme Catalysis, University of Greifswald, Greifswald, Germany.
Cysteine cathepsins such as cathepsin B and L play an important role in numerous diseases like acute pancreatitis or SARS-CoV-2 and therefore have high potential for the development of new therapeutics. To be able to screen for potent and selective inhibitors sufficient amounts of protein are required. Here, we present an easy and efficient protocol for the recombinant expression of soluble and active murine cathepsin B and L.
View Article and Find Full Text PDFGlycobiology
September 2024
Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, United States.
SRD5A3-CDG is a congenital disorder of glycosylation (CDG) resulting from pathogenic variants in SRD5A3 and follows an autosomal recessive inheritance pattern. The enzyme encoded by SRD5A3, polyprenal reductase, plays a crucial role in synthesizing lipid precursors essential for N-linked glycosylation. Despite insights from functional studies into its enzymatic function, there remains a gap in understanding global changes in patient cells.
View Article and Find Full Text PDFMol Genet Metab
October 2024
Department of Molecular Cell Biology and Medicine, Graduate School of Biomedical Sciences, Tokushima University, 1-78-1, Sho-machi, Tokushima 770-8505, Japan. Electronic address:
We previously expressed a chimeric protein in which the small heat-shock protein αB-crystallin (αBC) is fused at its N-terminus to the C-terminus of the first transmembrane segment of the endoplasmic reticulum (ER) protein mitsugumin 23 and confirmed its localization to the ER. Moreover, overexpression of this N-terminally modified αBC was shown to prevent the aggregation of the coexpressed R120G αBC variant, which is highly aggregation-prone and associated with the hereditary myopathy αB-crystallinopathy. To uncover a molecular mechanism by which the ER-anchored αBC negatively regulates the protein aggregation, we isolated proteins that bind to the ER-anchored αBC and identified the lysosomal protease cathepsin D (CTSD) as one such interacting protein.
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