ジャーナル: Structure / 年: 2018 タイトル: N-Terminal Domains of Cardiac Myosin Binding Protein C Cooperatively Activate the Thin Filament. 著者: Cristina Risi / Betty Belknap / Eva Forgacs-Lonart / Samantha P Harris / Gunnar F Schröder / Howard D White / Vitold E Galkin / 要旨: Muscle contraction relies on interaction between myosin-based thick filaments and actin-based thin filaments. Myosin binding protein C (MyBP-C) is a key regulator of actomyosin interactions. Recent ...Muscle contraction relies on interaction between myosin-based thick filaments and actin-based thin filaments. Myosin binding protein C (MyBP-C) is a key regulator of actomyosin interactions. Recent studies established that the N'-terminal domains (NTDs) of MyBP-C can either activate or inhibit thin filaments, but the mechanism of their collective action is poorly understood. Cardiac MyBP-C (cMyBP-C) harbors an extra NTD, which is absent in skeletal isoforms of MyBP-C, and its role in regulation of cardiac contraction is unknown. Here we show that the first two domains of human cMyPB-C (i.e., C0 and C1) cooperate to activate the thin filament. We demonstrate that C1 interacts with tropomyosin via a positively charged loop and that this interaction, stabilized by the C0 domain, is required for thin filament activation by cMyBP-C. Our data reveal a mechanism by which cMyBP-C can modulate cardiac contraction and demonstrate a function of the C0 domain.
分子量: 11507.176 Da / 分子数: 4 / 由来タイプ: 天然 / 由来: (天然) Sus scrofa (ブタ)
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実験情報
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実験
実験
手法: 電子顕微鏡法
EM実験
試料の集合状態: HELICAL ARRAY / 3次元再構成法: らせん対称体再構成法
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試料調製
構成要素
ID
名称
タイプ
詳細
Entity ID
Parent-ID
由来
1
human cardiac myosin binding protein C C1 Ig-domain bound to native cardiac thin filament
COMPLEX
Sample contains actin, tropomyosin, troponin complex, myosin binding protein-C C0-C1 Ig domains. Only C1 Ig-domain bound to the cardiac thin filament is visualized in the map
all
0
MULTIPLESOURCES
2
Actin, cytoplasmic2
COMPLEX
#1
1
RECOMBINANT
3
Myosin-binding protein C, cardiac-type
COMPLEX
#2
1
RECOMBINANT
4
Tropomyosin
COMPLEX
#3
1
NATURAL
分子量
実験値: NO
由来(天然)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
1
2
Homo sapiens (ヒト)
9606
2
3
Homo sapiens (ヒト)
9606
3
4
Sus scrofa (ブタ)
9823
由来(組換発現)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
1
2
Homo sapiens (ヒト)
9606
2
3
Escherichia coli (大腸菌)
562
緩衝液
pH: 7
試料
包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES
試料支持
グリッドの材料: COPPER / グリッドのサイズ: 300 divisions/in.
急速凍結
装置: FEI VITROBOT MARK II / 凍結剤: ETHANE / 湿度: 95 % / 凍結前の試料温度: 294 K