부산대학교 도서관

Enzymatic probes of chromatin structure reveal accessible versus inaccessible chromatin states, while super-resolution microscopy reveals a continuum of chromatin compaction states. Characterizing histone H2B movements by single-molecule tracking (SMT), we resolved chromatin domains ranging from low to high mobility and displaying different subnuclear localizations patterns. Heterochromatin constituents correlated with the lowest mobility chromatin, whereas transcription factors varied widely with regard to their respective mobility with low- or high-mobility chromatin. Pioneer transcription factors, which bind nucleosomes, can access the low-mobility chromatin domains, whereas weak or non-nucleosome binding factors are excluded from the domains and enriched in higher mobility domains. Nonspecific DNA and nucleosome binding accounted for most of the low mobility of strong nucleosome interactor FOXA1. Our analysis shows how the parameters of the mobility of chromatin-bound factors, but not their diffusion behaviors or SMT-residence times within chromatin, distinguish functional characteristics of different chromatin-interacting proteins. • Dual-motion parameter analysis of histone H2B defines a mobility landscape • The chromatin mobility landscape, not residence times, reflects functional states • Heterochromatin constituents are variably present in low-mobility chromatin • Low-mobility chromatin exploration is enabled by nucleosome interactions A two-parameter assessment of motion tracks of histone H2B in living cells unveils a chromatin mobility landscape that explains differences in single-molecule behavior and function of diverse heterochromatin regulators and transcription factors. [ABSTRACT FROM AUTHOR]