Open AccessNa+ and K+ Ions Differently Affect Nucleosome Structure, Stability, and Interactions with Proteins
Author(s) -
Т. В. Андреева,
N. V. Maluchenko,
Anastasiia L. Sivkina,
О. В. Чертков,
М. Е. Валиева,
Elena Kotova,
Mikhaǐl P. Kirpichnikov,
Vasily M. Studitsky,
Аlexey V. Feofanov
Publication year - 2021
Publication title -
microscopy and microanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.521
H-Index - 69
eISSN - 1435-8115
pISSN - 1431-9276
DOI - 10.1017/s1431927621013751
Subject(s) - nucleosome , chromatin , biophysics , ion , dna , chemistry , crystallography , histone , transcription (linguistics) , linker dna , biochemistry , biology , linguistics , philosophy , organic chemistry
Inorganic ions are essential factors stabilizing nucleosome structure; however, many aspects of their effects on DNA transactions in chromatin remain unknown. Here, differential effects of K+ and Na+ on the nucleosome structure, stability, and interactions with protein complex FACT (FAcilitates Chromatin Transcription), poly(ADP-ribose) polymerase 1, and RNA polymerase II were studied using primarily single-particle Förster resonance energy transfer microscopy. The maximal stabilizing effect of K+ on a nucleosome structure was observed at ca. 80–150 mM, and it decreased slightly at 40 mM and considerably at >300 mM. The stabilizing effect of Na+ is noticeably lower than that of K+ and progressively decreases at ion concentrations higher than 40 mM. At 150 mM, Na+ ions support more efficient reorganization of nucleosome structure by poly(ADP-ribose) polymerase 1 and ATP-independent uncoiling of nucleosomal DNA by FACT as compared with K+ ions. In contrast, transcription through a nucleosome is nearly insensitive to K+ or Na+ environment. Taken together, the data indicate that K+ environment is more preserving for chromatin structure during various nucleosome transactions than Na+ environment.