TY - JOUR
T1 - Actin-binding domain of Rng2 sparsely bound on F-actin strongly inhibits actin movement on myosin II
AU - Hayakawa, Yuuki
AU - Takaine, Masak
AU - Ngo, Kien Xuan
AU - Imai, Taiga
AU - Yamada, Masafumi D.
AU - Behjat, Arash Badami
AU - Umeda, Kenichi
AU - Hirose, Keiko
AU - Yurtsever, Ayhan
AU - Kodera, Noriyuki
AU - Tokuraku, Kiyotaka
AU - Numata, Osamu
AU - Fukuma, Takeshi
AU - Ando, Toshio
AU - Nakano, Kentaro
AU - Uyeda, Taro Qp
N1 - Publisher Copyright:
© 2022 Hayakawa et al.
PY - 2023/1/1
Y1 - 2023/1/1
N2 - We report a case in which sub-stoichiometric binding of an actin-binding protein has profound structural and functional consequences, providing an insight into the fundamental properties of actin regulation. Rng2 is an IQGAP contained in contractile rings in the fission yeast Schizosaccharomyces pombe Here, we used high-speed atomic force microscopy and electron microscopy and found that sub-stoichiometric binding of the calponin-homology actin-binding domain of Rng2 (Rng2CHD) induces global structural changes in skeletal muscle actin filaments, including shortening of the filament helical pitch. Sub-stoichiometric binding of Rng2CHD also reduced the affinity between actin filaments and muscle myosin II carrying ADP and strongly inhibited the motility of actin filaments on myosin II in vitro. On skeletal muscle myosin II-coated surfaces, Rng2CHD stopped the actin movements at a binding ratio of 11%. Rng2CHD also inhibited actin movements on myosin II of the amoeba Dictyostelium, but in this case, by detaching actin filaments from myosin II-coated surfaces. Thus, sparsely bound Rng2CHD induces apparently cooperative structural changes in actin filaments and inhibits force generation by actomyosin II.
AB - We report a case in which sub-stoichiometric binding of an actin-binding protein has profound structural and functional consequences, providing an insight into the fundamental properties of actin regulation. Rng2 is an IQGAP contained in contractile rings in the fission yeast Schizosaccharomyces pombe Here, we used high-speed atomic force microscopy and electron microscopy and found that sub-stoichiometric binding of the calponin-homology actin-binding domain of Rng2 (Rng2CHD) induces global structural changes in skeletal muscle actin filaments, including shortening of the filament helical pitch. Sub-stoichiometric binding of Rng2CHD also reduced the affinity between actin filaments and muscle myosin II carrying ADP and strongly inhibited the motility of actin filaments on myosin II in vitro. On skeletal muscle myosin II-coated surfaces, Rng2CHD stopped the actin movements at a binding ratio of 11%. Rng2CHD also inhibited actin movements on myosin II of the amoeba Dictyostelium, but in this case, by detaching actin filaments from myosin II-coated surfaces. Thus, sparsely bound Rng2CHD induces apparently cooperative structural changes in actin filaments and inhibits force generation by actomyosin II.
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U2 - 10.26508/lsa.202201469
DO - 10.26508/lsa.202201469
M3 - Article
C2 - 36288901
AN - SCOPUS:85140809288
SN - 2575-1077
VL - 6
JO - Life Science Alliance
JF - Life Science Alliance
IS - 1
ER -