Two conserved lysines at the 50/20-kDa junction of myosin are necessary for triggering actin activation

被引:68
作者
Joel, PB
Trybus, KM
Sweeney, HL
机构
[1] Univ Vermont, Coll Med, Dept Mol Physiol & Biophys, Burlington, VT 05405 USA
[2] Univ Penn, Sch Med, Dept Physiol, Philadelphia, PA 19104 USA
关键词
D O I
10.1074/jbc.M006930200
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
Actin stimulates myosin's activity by inducing structural alterations that correlate with the transition from a weakly to a strongly bound state, during which time inorganic phosphate (P-i) is released from myosin's active site. The surface loop at the 50/20-kDa junction of myosin (loop 2) is part of the actin interface. Here we demonstrate that elimination of two highly conserved lysines at the C-terminal end of loop 2 specifically blocks the ability of heavy meromyosin to undergo a weak to strong binding transition with actin in the presence of ATP, Removal of these lysines has no effect on strong binding in the absence of nucleotide, on the rate of ADP binding or release, or on the basal ATPase activity. We further show that the 16 amino acids of loop 2 preceding the lysine-rich region are not essential for actin activation, although they do modulate myosin's affinity for actin in the presence of ATP. We conclude that interaction of the conserved lysines with acidic residues in subdomain I of actin either triggers a structural change or stabilizes a conformation that is necessary for actin-activated release of P-i and completion of the ATPase cycle.
引用
收藏
页码:2998 / 3003
页数:6
相关论文
共 36 条
[1]   SELECTIVE CLEAVAGE OF THE CONNECTOR SEGMENTS WITHIN THE MYOSIN-S1 HEAVY-CHAIN BY STAPHYLOCOCCAL PROTEASE [J].
CHAUSSEPIED, P ;
BERTRAND, R ;
AUDEMARD, E ;
PANTEL, P ;
DERANCOURT, J ;
KASSAB, R .
FEBS LETTERS, 1983, 161 (01) :84-88
[2]   MODIFYING PRESELECTED SITES ON PROTEINS - THE STRETCH OF RESIDUES 633-642 OF THE MYOSIN HEAVY-CHAIN IS PART OF THE ACTIN-BINDING SITE [J].
CHAUSSEPIED, P ;
MORALES, MF .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1988, 85 (20) :7471-7475
[3]   SYNTHETIC PEPTIDE OF THE SEQUENCE-632-642 ON MYOSIN SUBFRAGMENT-1 INHIBITS ACTOMYOSIN ATPASE ACTIVITY [J].
CHEUNG, P ;
REISLER, E .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1992, 189 (02) :1143-1149
[4]  
COOK RK, 1993, J BIOL CHEM, V268, P2410
[5]   ACTOMYOSIN INTERACTIONS IN THE PRESENCE OF ATP AND THE N-TERMINAL SEGMENT OF ACTIN [J].
DASGUPTA, G ;
REISLER, E .
BIOCHEMISTRY, 1992, 31 (06) :1836-1841
[6]   Crystal structure of a vertebrate smooth muscle myosin motor domain and its complex with the essential light chain: Visualization of the pre-power stroke state [J].
Dominguez, R ;
Freyzon, Y ;
Trybus, KM ;
Cohen, C .
CELL, 1998, 94 (05) :559-571
[7]   X-RAY STRUCTURES OF THE MYOSIN MOTOR DOMAIN OF DICTYOSTELIUM-DISCOIDEUM COMPLEXED WITH MGADP-CENTER-DOT-BEFX AND MGADP-CENTER-DOT-ALF4- [J].
FISHER, AJ ;
SMITH, CA ;
THODEN, JB ;
SMITH, R ;
SUTOH, K ;
HOLDEN, HM ;
RAYMENT, I .
BIOCHEMISTRY, 1995, 34 (28) :8960-8972
[8]   Modulation of actin affinity and actomyosin adenosine triphosphatase by charge changes in the myosin motor domain [J].
Furch, M ;
Geeves, MA ;
Manstein, DJ .
BIOCHEMISTRY, 1998, 37 (18) :6317-6326
[9]   Structural mechanism of muscle contraction [J].
Geeves, MA ;
Holmes, KC .
ANNUAL REVIEW OF BIOCHEMISTRY, 1999, 68 :687-728
[10]  
GEEVES MA, 1991, BIOCHEM J, V274, P1