Cysteine proteases are involved in the degradation of intracellular and extracellular proteins, although their precise roles in vivo are not well understood. Here we characterise a genetic mutant of the Caenorhabditis elegans cathepsin L protease gene cpl-1. CPL-1 is provided maternally and is essential for C. elegans embryogenesis. Immunofluorescence and electron microscopy data show that yolk endocytosis and initial yolk platelet formation occur normally in cpl-1 mutant oocytes and embryos. However, at around the 8-12 cell stage of embryogenesis, yolk platelets begin to aggregate and these enlarged yolk platelets fill the cytoplasm of cpl-1 mutant embryos. Coincident with this aggregation is loss of fluorescence from a yolk green fluorescent protein (YP170::GFP). This suggests that loss of CPL-1 activity leads to aberrant processing and/or conformational changes in yolk proteins, resulting in abnormal platelet fusion. This study has relevance to the abnormal fusion and aggregation of lysosomes in cathepsin L-deficient mice and to other lysosomal disorders.
Cathepsin L protease (CPL-1) is essential for yolk processing during embryogenesis in Caenorhabditis elegans Available to Purchase
Collette Britton, Linda Murray; Cathepsin L protease (CPL-1) is essential for yolk processing during embryogenesis in Caenorhabditis elegans. J Cell Sci 1 October 2004; 117 (21): 5133–5143. doi: https://doi.org/10.1242/jcs.01387
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