Cannon MJ, et al 2002 reported the Expression and Regulation of Interferon-{gamma}-Inducible Proteasomal Subunits LMP7 and LMP10 in the Bovine Corpus Luteum.
The proteasome is a large, polymeric protease complex responsible for intracellular protein degradation, as well as generation of peptides that bind to class I MHC molecules. Interferon-gamma induces expression of alternative proteasomal subunits that affect intracellular protein degradation, thereby changing the types of peptides that bind to class I MHC molecules. These alterations in class I MHC peptides can influence whether cells and tissues are tolerated by the immune system. Expression of two interferon-gamma-inducible proteasomal subunits, LMP7 and LMP10, in bovine luteal tissue was examined in this study. Northern analysis revealed the presence of mRNA encoding LMP7 and LMP10 in luteal tissue. Steady-state amounts of LMP7 mRNA did not change during the estrous cycle, but LMP10 mRNA was low in early CL and elevated in midcycle and late CL. Tumor necrosis factor-alpha alone and in the presence of LH and/or PGF2alpha elevated steady-state amounts of LMP10 mRNA, but did not affect LMP7 mRNA, in cultured luteal cells. Immunohistochemistry revealed the presence of LMP10 primarily in small luteal cells. Numbers of LMP10 positive cells were lower in early CL compared to midcycle and late CL. The finding that interferon-gamma-inducible proteasomal subunits are expressed in luteal tissue when the CL is fully functional was unexpected, and suggests that proteasomes present in luteal cells may generate peptides capable of stimulating a class I MHC-dependent inflammatory response.
NCBI Summary:
The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is located in the class II region of the MHC (major histocompatibility complex). Expression of this gene is induced by gamma interferon and this gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Proteolytic processing is required to generate a mature subunit. Two alternative transcripts encoding two isoforms have been identified; both isoforms are processed to yield the same mature subunit.
General function
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Cellular localization
Cytoplasmic
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Ovarian function
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Expression regulated by
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Ovarian localization
Luteal cells
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Assessment of the risk of blastomere biopsy during pre-implantation genetic diagnosis in a mouse model: reducing female ovary function with an increase in age by proteomics method. Yu Y 2013 et al.
Pre-implantation genetic diagnosis (PGD) is important for screening genetic and chromosome mutations in embryos so that the efficiency of assisted reproductive treatment can be increased and birth defects can be decreased; however, some studies have reported a risk from this technology, as well as other assisted reproductive technologies. We have developed a PGD mouse model to assess the potential effects of blastomere biopsy on the fertility of female mice at different ages. We showed that female fertility was decreased in PGD the mouse model with an increase in age. Moreover, the ovarian weight, serum hormone levels, and the number of primordial, primary, pre-antral, and antral stage follicles were also decreased in the middle-aged PGD mouse model. To elucidate the underlying molecular mechanism, ovarian tissues from adult PGD and control mice underwent proteomics analysis. Of the 23 differentially-expressed proteins which were screened for in both groups, 3 proteins (PSMB8, ALDH1A1, and HSPA4) were selected and identified by Western blotting and quantitative RT-PCR methods, which showed the 3 proteins to regulate 12 cellular pathways. Furthermore, these 3 proteins were shown to be located in ovarian tissues and the dynamic changes of expression profiling in middle-aged PGD and control mice were demonstrated. The present study showed that blastomere biopsy technology impairs fertility when mice are middle-aged, which possibly resulted in abnormal expression profiling of PSMB8, ALDH1A1, and HSPA4 proteins. Thus, additional studies should be performed to assess the overall risk of blastomere biopsies during PGD procedures.
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