Rice proteomics: recent developments and analysis of nuclear proteins.

Rice is the most important cereal crop in Asia, and is considered as a model cereal plant for genetic and molecular studies. An immense progress has been made in rice genome sequence analysis during the last decade. This prompted the researcher to identify the functions, modifications, and regulations of every encoded protein. Proteome analysis provides information to predict the translation and relative concentration of gene products, including the extent of modification, none of which can be accurately predicted from the nucleic acid sequence alone. During the last couple of years, considerable researches were conducted to analyze rice proteome, and only recently a remarkable progress has been made to systematically analyze and characterize the functional role of various tissues and organelles in rice. In this review, the rice proteomic research has been compiled and also presented a comprehensive analysis of rice nuclear proteins. In rice nucleus, 549 proteins were resolved using 2D-PAGE. Among them, 257 proteins were systematically analyzed by Edman sequencing and mass spectrometry and identified 190 proteins following database searching (http://gene64.dna.affrc.go.jp/RPD/main.html). The identified proteins were sorted into different functional categories. In these data, the proteins involved in signaling and gene regulations dominated others, reflecting the role of nucleus in gene expression and regulation.