TY - JOUR
T1 - Stabilization of nucleosomes by histone tails and by FACT revealed by spFRET microscopy
AU - Valieva, Maria E.
AU - Gerasimova, Nadezhda S.
AU - Kudryashova, Kseniya S.
AU - Kozlova, Anastasia L.
AU - Kirpichnikov, Mikhail P.
AU - Hu, Qi
AU - Botuyan, Maria Victoria
AU - Mer, Georges
AU - Feofanov, Alexey V.
AU - Studitsky, Vasily M.
N1 - Publisher Copyright:
© 2017 by the authors; licensee MDPI, Basel, Switzerland.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - A correct chromatin structure is important for cell viability and is tightly regulated by numerous factors. Human protein complex FACT (facilitates chromatin transcription) is an essential factor involved in chromatin transcription and cancer development. Here FACT-dependent changes in the structure of single nucleosomes were studied with single-particle Förster resonance energy transfer (spFRET) microscopy using nucleosomes labeled with a donor-acceptor pair of fluorophores, which were attached to the adjacent gyres of DNA near the contact between H2A-H2B dimers. Human FACT and its version without the C-terminal domain (CTD) and the high mobility group (HMG) domain of the structure-specific recognition protein 1 (SSRP1) subunit did not change the structure of the nucleosomes, while FACT without the acidic C-terminal domains of the suppressor of Ty 16 (Spt16) and the SSRP1 subunits caused nucleosome aggregation. Proteolytic removal of histone tails significantly disturbed the nucleosome structure, inducing partial unwrapping of nucleosomal DNA. Human FACT reduced DNA unwrapping and stabilized the structure of tailless nucleosomes. CTD and/or HMG domains of SSRP1 are required for this FACT activity. In contrast, previously it has been shown that yeast FACT unfolds (reorganizes) nucleosomes using the CTD domain of SSRP1-like Pol I-binding protein 3 subunit (Pob3). Thus, yeast and human FACT complexes likely utilize the same domains for nucleosome reorganization and stabilization, respectively, and these processes are mechanistically similar.
AB - A correct chromatin structure is important for cell viability and is tightly regulated by numerous factors. Human protein complex FACT (facilitates chromatin transcription) is an essential factor involved in chromatin transcription and cancer development. Here FACT-dependent changes in the structure of single nucleosomes were studied with single-particle Förster resonance energy transfer (spFRET) microscopy using nucleosomes labeled with a donor-acceptor pair of fluorophores, which were attached to the adjacent gyres of DNA near the contact between H2A-H2B dimers. Human FACT and its version without the C-terminal domain (CTD) and the high mobility group (HMG) domain of the structure-specific recognition protein 1 (SSRP1) subunit did not change the structure of the nucleosomes, while FACT without the acidic C-terminal domains of the suppressor of Ty 16 (Spt16) and the SSRP1 subunits caused nucleosome aggregation. Proteolytic removal of histone tails significantly disturbed the nucleosome structure, inducing partial unwrapping of nucleosomal DNA. Human FACT reduced DNA unwrapping and stabilized the structure of tailless nucleosomes. CTD and/or HMG domains of SSRP1 are required for this FACT activity. In contrast, previously it has been shown that yeast FACT unfolds (reorganizes) nucleosomes using the CTD domain of SSRP1-like Pol I-binding protein 3 subunit (Pob3). Thus, yeast and human FACT complexes likely utilize the same domains for nucleosome reorganization and stabilization, respectively, and these processes are mechanistically similar.
KW - FACT
KW - Facilitates chromatin transcription
KW - Nucleosome
KW - SSRP1
KW - Spt16
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U2 - 10.3390/cancers9010003
DO - 10.3390/cancers9010003
M3 - Article
AN - SCOPUS:85009726014
SN - 2072-6694
VL - 9
JO - Cancers
JF - Cancers
IS - 1
M1 - 3
ER -