Onset of grain filling is associated with a change in properties of linker histone variants in maize kernels
- 173 Downloads
In maize kernel development, the onset of grain-filling represents a major developmental switch that correlates with a massive reprogramming of gene expression. We have isolated chromosomal linker histones from developing maize kernels before (11 days after pollination, dap) and after (16 dap) initiation of storage synthesis. Six linker histone gene products were identified by MALDI-TOF mass spectrometry. A marked shift of around 4 pH units was observed for the linker histone spot pattern after 2D-gel electrophoresis when comparing the proteins of 11 and 16 dap kernels. The shift from acidic to more basic protein forms suggests a reduction in the level of post-translational modifications of linker histones during kernel development. Analysis of their DNA-binding affinity revealed that the different linker histone gene products bind double-stranded DNA with similar affinity. Interestingly, the linker histones isolated from 16 dap kernels consistently displayed a lower affinity for DNA than the proteins isolated from 11 dap kernels. These findings suggest that the affinity for DNA of the linker histones may be regulated by post-translational modification and that the reduction in DNA affinity could be involved in a more open chromatin during storage synthesis.
KeywordsChromatin DNA interaction H1 Linker histone 2D-gel electrophoresis
Days after pollination
Matrix-assisted laser desorption/ionisation–time-of-flight mass spectrometry
This work was supported by grants from the Danish Research Council to Klaus Grasser. Rainer Kalamajka was recipient of a fellowship from the German Academic Exchance Service (DAAD).
- Gobom J, Nordhoff E, Migorodskaya E, Ekman R, Roepstorff P (1999) Sample purification and preparation technique based on nano-scale reversed-phase columns for the sensitive analysis of complex peptide mixtures by matrix-assisted laser desorption/ionization mass spectrometry. J Mass Spectrom 34:105–116CrossRefPubMedGoogle Scholar
- Prymakowska-Bosak M, Przewloka MR, Iwkiewicz J, Egierszdorff S, Kuras M, Chaubet N, Gigot C, Spiker S, Jerzmanowski A (1996) Histone H1 overexpressed to high level in tobacco affects certain developmental programs but has limited effect on basal cellular functions. Proc Natl Acad Sci USA 93:10250–10255CrossRefPubMedGoogle Scholar
- Srebeva L, Iosifidu M, Chimshirova K, Zlatanova J (1989) Occurrence of histone H10-related fraction in differentiated maize roots. Biochim Biophys Acta 1008:346–350Google Scholar