%0 Journal Article %T Mass spectrometry analysis of the variants of histone H3 and H4 of soybean and their post-translational modifications %A Tao Wu %A Tiezheng Yuan %A Sau-Na Tsai %A Chunmei Wang %A Sai-Ming Sun %A Hon-Ming Lam %A Sai-Ming Ngai %J BMC Plant Biology %D 2009 %I BioMed Central %R 10.1186/1471-2229-9-98 %X In soybean leaves, mono-, di- and tri-methylation at Lysine 4, Lysine 27 and Lysine 36, and acetylation at Lysine 14, 18 and 23 were detected in HISTONE H3. Lysine 27 was prone to being mono-methylated, while tri-methylation was predominant at Lysine 36. We also observed that Lysine 27 methylation and Lysine 36 methylation usually excluded each other in HISTONE H3. Although methylation at HISTONE H3 Lysine 79 was not reported in A. thaliana, mono- and di-methylated HISTONE H3 Lysine 79 were detected in soybean. Besides, acetylation at Lysine 8 and 12 of HISTONE H4 in soybean were identified. Using a combination of mass spectrometry and nano-liquid chromatography, two variants of HISTONE H3 were detected and their modifications were determined. They were different at positions of A31F41S87S90 (HISTONE variant H3.1) and T31Y41H87L90 (HISTONE variant H3.2), respectively. The methylation patterns in these two HISTONE H3 variants also exhibited differences. Lysine 4 and Lysine 36 methylation were only detected in HISTONE H3.2, suggesting that HISTONE variant H3.2 might be associated with actively transcribing genes. In addition, two variants of histone H4 (H4.1 and H4.2) were also detected, which were missing in other organisms. In the histone variant H4.1 and H4.2, the amino acid 60 was isoleucine and valine, respectively.This work revealed several distinct variants of soybean histone and their modifications that were different from A. thaliana, thus providing important biological information toward further understanding of the histone modifications and their functional significance in higher plants.Histone modifications and histone variants play critical roles in regulating gene expression, modulating the cell cycle, and are responsible for maintaining genome stability [1-3]. The fundamental structural unit of chromatin in eukaryotic cells is the nucleosome, that consists of 146 base pairs (bp) of DNA wrapped around a histone octamer, each of which is formed by two cop %U http://www.biomedcentral.com/1471-2229/9/98