Smooth muscle α-tropomyosin crosslinks to caldesmon, to actin and to myosin subfragment 1 on the muscle thin filament

被引：14

作者：

Golitsina, NL

Lehrer, SS ^{[1
]}

机构：

[1] Boston Biomed Res Inst, Muscle Res Grp, Boston, MA 02114 USA

[2] Harvard Univ, Sch Med, Dept Neurol, Boston, MA 02115 USA

来源：

FEBS LETTERS | 1999年 / 463卷 / 1-2期

关键词：

muscle thin filament; smooth muscle tropomyosin Cys mutant; caldesmon; actin; UV crosslinking;

D O I：

10.1016/S0014-5793(99)01589-6

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

To obtain proximity information between tropomyosin (Tm) and caldesmon (CaD) on the muscle thin filament, we cloned gizzard alpha Tm and created two single Cys mutants S56C/ C190S (56Tm) and D100C/C190S (100Tm), They were labeled with benzophenone maleimide (BPM) and UV-irradiated on thin filaments. One chain of BPM-56Tm and two chains of BPM-100Tm crosslinked to CaD, Only BPM-100Tm crosslinked to actin in the absence and presence of CaD and binding of low ratios of myosin subfragment 1 (S1) prevented the crosslinking. Tm-S1 crosslinks were produced when actin Tm mas saturated with S1, Thus, CaD on the actin Tm filament is located < 10 Angstrom away from Tm amino acids 56 and 100; in the closed state of the actin-Tm filament, Tm residue 100 is located close to the actin surface and is moved further away in the S1-induced open state; in the open state, S1 binds close to Tm, (C) 1999 Federation of European Biochemical Societies.

引用

页码：146 / 150

页数：5

共 36 条

[1]

CHALOVICH JM, 1987, J BIOL CHEM, V262, P5711

[2] A MOSAIC MULTIPLE-BINDING MODEL FOR THE BINDING OF CALDESMON AND MYOSIN SUBFRAGMENT-1 TO ACTIN [J].