Cathepsins H (CTSH), L (CTSL), B (CTSB) and S (CTSS) are papain family
cysteine proteinases involved in a variety of physiologic processes such as
proenzyme activation, enzyme inactivation, antigen presentation, hormone
maturation, tissue remodeling, and bone matrix resorption
NCBI Summary:
The protein encoded by this gene, a member of the peptidase C1 family, is a lysosomal cysteine proteinase that may participate in the degradation of antigenic proteins to peptides for presentation on MHC class II molecules. The encoded protein can function as an elastase over a broad pH range in alveolar macrophages. Transcript variants utilizing alternative polyadenylation signals exist for this gene.
General function
Enzyme, Hydrolase, Peptidase/Protease
Comment
Cellular localization
Secreted, Cytoplasmic
Comment
Ovarian function
Comment
Expression regulated by
Comment
Ovarian localization
Oocyte, Theca, Luteal cells
Comment
S. Oksjoki reported the differential expression patterns of cathepsins B, H, K, L and S in the mouse ovary.
Cathepsins B, H, K, L and S belong to a family of lysosomal cysteine proteinases which participate in a variety of proteolytic processes, including degradation of extracellular matrix. Although the presence of cathepsin mRNAs in the ovary has been reported earlier, very little information is available on their temporospatial expression. In the present study, Northern analysis revealed cyclic changes in the mRNA levels for cathepsins B, H, K, L and S during the 4-day oestrous cycle in the mouse ovary. Immunohistochemical localization revealed distinct expression patterns suggesting different functions for the cathepsins studied. Strong cathepsin H staining was sharply defined in theca externa which also stained for cathepsins K and S. Corpus luteum was the predominant location of cathepsin L. The distribution of cathepsin S resembled that of cathepsin L. The developing oocyte stained positive for all cathepsins. In-situ hybridization confirmed the differential production of cathepsin mRNAs by granulosa, thecal and luteal cells. These complex temporal and spatial expression patterns at different stages of the oestrous cycle and follicular development suggest divergent functions for specific cathepsins in follicular development, growth and rupture.