Lysosomal cysteine proteases: more than scavengers

Macrophage and microglia ontogeny in the mouse visual system can be traced by the expression of Cathepsins B and D

“…The cathepsin family consists of cysteine, aspartate, and serine lysosomal proteases that play an important role in many physiological and pathological processes (Turk et al, 2000;Sloane et al, 2005;Mohamed and Sloane, 2006;Vasiljeva et al, 2007;Conus and Simon et al, 2008). Among these, cathepsin B is involved in the degradation of cellular proteins in lysosomes and functions as an endopeptidase at neutral pH.…”

Reduced tumour cell proliferation and delayed development of high-grade mammary carcinomas in cathepsin B-deficient mice

“…Eleven human cysteine cathepsin genes are present in the human genome: cathepsins B, C (dipeptidyl peptidase I), F, H, K, L, O, S, V (L2), W (lymphopain) and X (Z) (Rossi et al, 2004). Despite their general lysosomal localization, active cathepsins have been found extracellularly and in cellular compartments other than endosomes and lysosomes and are involved functionally in a variety of physiological and pathological processes (Turk et al, 2000;Vasiljeva et al, 2007). There is increasing evidence that cysteine proteases, mostly cathepsins B and L and, to a lesser extent, cathepsins X, H, S and K, contribute to the proteolytic events during tumour progression (Jedeszko and Sloane, 2004).…”

Selective suppression of cathepsin L by antisense cDNA impairs human brain tumor cell invasion in vitro and promotes apoptosis

“…These are divided, based on their commonality of protein sequence, into two families: the cathepsin L -like family (L, H, V, K, S, W, F ) and the cathepsin B -like family (B, C, O, X, and so forth ), which also differ in other structural and functional biochemical characteristics. 1 Lysosomal peptidases are regulated at every level of their biosynthesis, including transcription, translation, posttranslational processing, carbohydrate maturation, and trafficking to lysosomes. The activation of lysosomal enzymes is triggered by lowering pH and limited proteolysis during the process in which endosomes maturate into lysosomes.…”

“…16 Besides caspases, other endopeptidases may be involved in the proteolytic cascades of apoptosis, 17 including other lysosomal cysteine proteases and their inhibitors stefins A and B. 1,18,19 As proteolytic cascades involved in invasion may interfere with those involved in apoptosis, 21 this present study was designed to investigate possible roles of lysosomal cysteine endopeptidase cathepsin L in both invasion and staurosporine -induced apoptosis. We demonstrated that in the human glioblastoma cell line IPTP ( a ) alteration in cathepsin L expression simultaneously affects both invasion and apoptosis, and (b ) decreased invasiveness is associated with increased response to apoptotic stimuli.…”