MUTATIONS OF AN ACTIN BINDING LOOP IN HUMAN NONMUSCLE MYOSIN IIA
MUTATIONS OF AN ACTIN BINDING LOOP IN HUMAN NONMUSCLE MYOSIN IIA
批准号:
6162725
负责人:
JAMES R. SELLERS
金额:
$0.0万
依托单位国家:
美国
项目类别:
财政年份:
--
资助国家:
美国
项目状态:
未结题
起止时间:
至
中文摘要
虽然有肌动蛋白和肌凝蛋白晶体,但分子细节
英文摘要
While there are crystals of actin and of myosin, the molecular details
of the interaction of myosin with actin are not well understood. There
is a biochemical or modeled structural evidence for interaction between
several areas of myosin with actin including a myosin surface loop that
begins with amino acid 391 and ends with amino acid 404 in the human
nonmuscle myosin IIA sequence based upon homology with the chicken
skeletal muscle myosin that was crystallized. This loop is postulated
to make direct contact with actin based on the Holmes-Rayment-Milligan
model for interaction with actin and myosin. In human cardiac myosin,
it contains a residue (Arg-403) that is mutated to a Gln or Trp to cause
hypertrophic cardiomyopathy (HCM). In Acanthamoeba and Dictyostelium
myosin I's and members of the myosin VI class, one of the residues in
this loop is invariably a serine or threonine. In the myosin I
molecules, phosphorylation of this Thr is required for activity. In
almost all other myosins, this residue is either a Glu or Asp,
suggesting that a negative charge at this residue is important for
activity. We have used site-directed mutagenesis coupled with
baculovirus expression of an HMM-like fragment of human nonmuscle IIA.
We mutated Arg-393 (equivalent to the HCM mutation in cardiac myosin)
to a Gln and Asp-399 (equivalent to the regulatory
phosphorylation/invariant negative charged residue) to a Lys. Both
mutants and wild-type HMM were well regulated by phosphorylation of the
20 kDa regulatory light chain. The Arg393Gln mutation results in a 25-
50% increase in the Vmax of the actin-activated MgATPase. The mutation
did not affect the rate of actin filament sliding in an in vitro
motility assay. The Asp399Lys mutation decreased the Vmax by 8-10 fold
and the rate of in vitro motility by a factor of two, supporting an
important role for the negative charge at this location. Neither
mutation had a significant effect on the amount of actin required for
half-maximal MgATPase activity and both are well regulated by their 20
kD light chain phosphorylation. We are currently studying other
mutations of this loop.
期刊论文(0)
专著(0)
科研奖励(0)
会议论文
EXPRESSION OF STUDIES OF MYOSIN V
-
批准号:6290443
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Studies Of Myosin V
-
批准号:6690561
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression studies of other unconventional myosins
-
批准号:6967009
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Chemical Inhibitors of Myosin Function
-
批准号:6967012
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression Studies of Other Unconventional Myosins
-
批准号:7734993
-
项目类别:
-
资助金额:$56.33万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Chemical Inhibitors of Myosin Function
-
批准号:7158542
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
STRUCTURAL AND FUNCTIONAL ANALYSIS OF DROSOPHILA MYOSIN
-
批准号:7158522
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Studies Of Myosin V
-
批准号:7158529
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression Studies of Myosin X
-
批准号:7594411
-
项目类别:
-
资助金额:$22.56万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression Studies of Other Unconventional Myosins
-
批准号:7594412
-
项目类别:
-
资助金额:$67.69万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
EXPRESSION OF STUDIES OF MYOSIN V
-
批准号:6109258
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
IN VITRO FUNCTIONAL STUDIES OF HUMAN CARDIAC MYOSIN
-
批准号:6109249
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
STRUCTURAL AND FUNCTIONAL ANALYSIS OF DROSOPHILA MYOSIN V
-
批准号:6290441
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Regulation Of Smooth and Nonmuscle Myosin
-
批准号:6817757
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Chemical Inhibitors of Myosin Function
-
批准号:6818044
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Studies Of Myosin V
-
批准号:6966997
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression Studies Of Other Unconventional Myosins
-
批准号:6690568
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Chemical Inhibitors Of Myosin Function
-
批准号:6690569
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Expression Studies of Other Unconventional Myosins
-
批准号:7321322
-
项目类别:
-
资助金额:$0.0万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
Regulation Of Smooth and Nonmuscle Myosin
-
批准号:7734965
-
项目类别:
-
资助金额:$37.55万
-
财政年份:--
-
负责人:JAMES R. SELLERS
-
依托单位:
海外基金