Database Commons

a catalog of worldwide biological databases

The testis is the male gonad responsible for spermatogenesis and male hormone secretion. The complicated processes of spermatogenesis and steroidogenesis determine the complexity of protein expression control in the testis. In this study, the heterogeneity of human testis proteins was investigated using 2-dimensional gel electrophoresis. A total of 847 protein spots corresponding to 462 unique proteins were identified successfully by mass spectrometry. Notable heterogeneity was evidenced by the presence of more than 1 spot with different molecular weight and/or Isoelectric point values for each of 180 different proteins. Analysis of the detected peptides of these proteins indicated that this heterogeneity was partly the result of alternative splicing and/or proteolysis. SP_PIR_Keywords analysis suggested that alternative initiation sites and various forms of posttranslational modification may also contribute toward this heterogeneity. Using Pro-Q Diamond phosphostain, 68 spots representing 52 proteins were stained, confirming the presence of phosphorylated forms of these proteins in the human testis. These data were used to establish a proteome reference database, which can be accessed over the Internet (http://reprod.njmu.edu.cn/2d). This database provides an initial reference map of the human testis and serves as a useful resource for comparative proteomics studies of the human testis under normal and pathological states. The abundant protein heterogeneity observed in this study and further investigation of its biological significance will contribute toward understanding protein expression regulation in the human testis and will generate insight into the molecular mechanism of spermatogenesis.

The mature oocyte contains the full complement of maternal proteins required for fertilization, the transition to zygotic transcription, and the beginning stages of embryogenesis. Many of these proteins have yet to be characterized. In this study, two-dimensional electrophoresis (2-DE) of mouse metaphase-II (MII) oocyte proteins, stained with silver staining or Pro-Q Diamond dye, was performed to describe the proteome and phosphoproteome of the mouse oocyte derived from ICR mice. A total of 869 selected protein spots, corresponding to 380 unique proteins, were identified successfully by mass spectrometry, in which 90 protein spots representing 53 unique proteins have been stained with Pro-Q Diamond, indicating that they are in phosphorylated forms. All identified proteins were bioinformatically annotated in detail and compared with the embryonic stem cell (ESC) proteome. A proteome reference database for the mouse oocyte was established from the protein data generated in this study, which can be accessed over the Internet ( http://reprod.njmu.edu.cn/2d). This database is the most detailed mouse oocyte proteomic database to date. It should be valuable in expanding our knowledge of the regulation of signaling in oogenesis, fertilization, and embryo development, while revealing potential mechanisms for epigenetic reprogramming.

The ovary plays a central role in oogenesis and gonadal hormone secretion. Proteomic analysis is a valuable approach for gaining an increased understanding of the molecular nature of the ovary. In this work, two-dimensional electrophoresis for protein separation followed by matrix-assisted laser desorption/ionization mass spectrometry and database searches, identified 231 protein spots corresponding to 138 individual proteins that were found in gels representing both the follicular and luteal phases. The data were used to construct a database online (http://reprod.njmu.edu.cn/2d). The identified proteins were functionally classified into seven groups: (1) cell signaling/communication, (2) cell division, (3) gene/protein expression, (4) metabolism, (5) cell structure and motility, (6) cell/organism defense, and (7) unclassified. Among the proteins identified, 47% had not been previously reported in the human ovary. In addition, a number of disease-related proteins were identified in this protein map, including some cancer- and polycystic ovarian syndrome-related proteins. Two proteins with phosphorylation were verified by Western blot analysis. Comparison of protein abundance between follicular and luteal stages produced seven protein spots that had been identified in our database. This study provides a preliminary reference map of normal human ovary that will form a basis for comparative studies on normal and pathological conditions of the human ovary and may serve as a potential tool for clinical diagnosis, therapeutics, and prognosis.