PMID- 8900193
OWN - NLM
STAT- MEDLINE
DCOM- 19961216
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 271
IP  - 43
DP  - 1996 Oct 25
TI  - An essential myosin light chain peptide induces supramaximal stimulation of 
      cardiac myofibrillar ATPase activity.
PG  - 27039-43
AB  - The N-terminal region of skeletal myosin light chain-1 (MLC-1) binds to the C 
      terminus of actin, yet the functional significance of this interaction is 
      unclear. We studied a fragment (MLC-pep; residues 5-14) of the ventricular MLC-1. 
      When added to rat cardiac myofibrils, 10 nM MLC-pep induced a supramaximal 
      increase in the MgATPase activity at submaximal Ca2+ levels with no effect at low 
      and maximal Ca2+ levels. A nonsense, scrambled sequence peptide had no effect at 
      any pCa value. MLC-pep did not affect myosin KEDTA and CaATPase activities or 
      actin-activated MgATPase activities in the absence or presence of tropomyosin. 
      The MLC-pep did not alter the ability of troponin I to inhibit MgATPase activity. 
      Moreover, when troponin I and troponin C were extracted from the myofibrils, the 
      MLC-pep lost its ability to stimulate the ATPase rate. This effect was fully 
      restored upon reconstitution of the extracted myofibrils with troponin I-troponin 
      C complex. Thus, activation of MgATPase activity by the peptide required a full 
      complement of thin filament regulatory proteins. Interestingly, the stimulatory 
      effect occurred at a ratio of 4 peptides to 1 thin filament, suggesting that the 
      peptide engages in a highly cooperative process that may involve activation of 
      the entire thin filament.
FAU - Rarick, H M
AU  - Rarick HM
AD  - Department of Physiology and Biophysics, College of Medicine, University of 
      Illinois, Chicago, Illinois 60612-7342, USA.
FAU - Opgenorth, T J
AU  - Opgenorth TJ
FAU - von Geldern, T W
AU  - von Geldern TW
FAU - Wu-Wong, J R
AU  - Wu-Wong JR
FAU - Solaro, R J
AU  - Solaro RJ
LA  - eng
GR  - F32-HL-09009/HL/NHLBI NIH HHS/United States
GR  - R01-HL-22231/HL/NHLBI NIH HHS/United States
GR  - R01-HL-49934/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Muscle Proteins)
RN  - 0 (Myosin Light Chains)
RN  - 0 (Peptide Fragments)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
SB  - IM
MH  - Adenosine Triphosphatases/antagonists & inhibitors/*metabolism
MH  - Amino Acid Sequence
MH  - Animals
MH  - Cattle
MH  - Enzyme Activation
MH  - Heart Ventricles/*drug effects/enzymology
MH  - Male
MH  - Molecular Sequence Data
MH  - Muscle Proteins/metabolism
MH  - Myocardial Contraction/drug effects
MH  - Myosin Light Chains/*chemistry
MH  - Peptide Fragments/*pharmacology
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Ventricular Function
EDAT- 1996/10/25 00:00
MHDA- 1996/10/25 00:01
CRDT- 1996/10/25 00:00
PHST- 1996/10/25 00:00 [pubmed]
PHST- 1996/10/25 00:01 [medline]
PHST- 1996/10/25 00:00 [entrez]
AID - S0021-9258(18)35417-6 [pii]
AID - 10.1074/jbc.271.43.27039 [doi]
PST - ppublish
SO  - J Biol Chem. 1996 Oct 25;271(43):27039-43. doi: 10.1074/jbc.271.43.27039.