2026-04-19T23:35:01Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/4268342026-03-13T04:29:01Zcom_2072_98col_2072_378192

00925njm 22002777a 4500 dc Lopez Ramos, Rita author Sarg, Bettina author Lindner, Herbert author Bartolomé Piñol, Salvador author Ponte Marull, Immaculada author Suau León, Pere author Roque Córdova, Alicia author 2015 Linker histones are involved in chromatin higher-order structure and gene regulation. We have successfully achieved partial phosphorylation of linker histones in chicken erythrocyte soluble chromatin with CDK2, as indicated by HPCE, MALDI-TOF and Tandem MS. We have studied the effects of linker histone partial phosphorylation on secondary structure and chromatin condensation. Infrared spectroscopy analysis showed a gradual increase of β-structure in the phosphorylated samples, concomitant to a decrease in α-helix/turns, with increasing linker histone phosphorylation. This conformational change could act as the first step in the phosphorylation-induced effects on chromatin condensation. A decrease of the sedimentation rate through sucrose gradients of the phosphorylated samples was observed, indicating a global relaxation of the 30-nm fiber following linker histone phosphorylation. Analysis of specific genes, combining nuclease digestion and qPCR, showed that phosphorylated samples were more accessible than unphosphorylated samples, suggesting local chromatin relaxation. Chromatin aggregation was induced by MgCl and analyzed by dynamic light scattering (DLS). Phosphorylated chromatin had lower percentages in volume of aggregated molecules and the aggregates had smaller hydrodynamic diameter than unphosphorylated chromatin, indicating that linker histone phosphorylation impaired chromatin aggregation. These findings provide new insights into the effects of linker histone phosphorylation in chromatin condensation. Linker histone partial phosphorylation : effects on secondary structure and chromatin condensation