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. Proteolytic processing is required to generate a mature subunit. Expression of this gene is induced by gamma interferon, and this gene product replaces catalytic subunit 2 (proteasome beta 7 subunit) in the immunoproteasome.
General function
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Comment
Expression regulated by
LH, Growth Factors/ cytokines
Comment
Ovarian localization
Luteal cells, Small luteal cells
Comment
Follicle stages
Primordial, Corpus luteum
Comment
Arraztoa JA, et al 2005 reported the identification of genes expressed in primate primordial oocytes.