NCBI Summary:
The modification of proteins with ubiquitin is an important cellular mechanism for targeting abnormal or short-lived proteins for degradation. Ubiquitination involves at least three classes of enzymes: ubiquitin-activating enzymes, or E1s, ubiquitin-conjugating enzymes, or E2s, and ubiquitin-protein ligases, or E3s. This gene encodes a member of the E2 ubiquitin-conjugating enzyme family. This enzyme functions in the ubiquitination of the tumor-suppressor protein p53, which is induced by an E3 ubiquitin-protein ligase. Two alternatively spliced transcript variants have been found for this gene and they encode distinct isoforms.
General function
Enzyme
Comment
Cellular localization
Cytoplasmic
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Ovarian function
Early embryo development
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Expression regulated by
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Ovarian localization
Oocyte
Comment
Maternal housekeeping proteins translated during bovine oocyte maturation and early embryo development. Massicotte L et al. Protein synthesis from maternal mRNA is needed to sustain oocyte maturation and embryo development prior to the maternal-embryonic transition (MET). Therefore, proteins that are expressed throughout this time are important and may be considered as maternal housekeeping proteins (MHKP). Our objectives were first, identify the translated protein patterns of bovine embryo development and secondly, determine the MHKP. Proteins synthesized during oocyte maturation and embryo development (2, 4 and 8-cell stages) were labeled using [S(35)]-Met and [S(35)]-Cys, and visualized by 2-DE. Embryos were cultured with alpha-amanitine to inhibit new transcription. Only 46 proteins were present throughout all stages. Ten spots were identified by MALDI-TOF and MS/MS: HSC71; HSP70; CypA; UCH-L1; GSTM5; Cct5; E-FABP; 2,3-BPGM, ubiquitin-conjugating enzyme E2D3; and beta-actin/gamma-actin. A new method called in silico protein identification confirmation was developed using EST databases. This method is a promising approach for use in rare tissue or from species with an incomplete protein database. This study has revealed that the translated protein patterns show a transition that brings the embryo to the MET. The needs in translated proteins between oocyte maturation and embryo development are different. In summary, this study represents the bases for future proteomics studies on bovine oocytes and embryos.