PMID- 10563788
OWN - NLM
STAT- MEDLINE
DCOM- 19991220
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 38
IP  - 46
DP  - 1999 Nov 16
TI  - Calmodulin kinase II chimeras used to investigate the structural requirements for 
      smooth muscle myosin light chain kinase autoinhibition and calmodulin-dependent 
      activation.
PG  - 15061-9
AB  - Segments of the autoregulatory domain of MK, a catalytically active fragment of 
      the monomeric smooth muscle myosin light chain kinase (smMLCK) (residues 
      472-972), were replaced with their counterparts from a homologous but multimeric 
      enzyme, calmodulin-dependent protein kinase II (CaM KII). Chimeric proteins in 
      which both the autoregulatory and oligomerization domains of CaM KII (residues 
      281-478) were substituted for residues 781-972 of smMLCK, MK(CK281-478), or only 
      the autoregulatory domain of CaM KII (residues 281-315) was exchanged for 
      residues 781-813 of smMLCK, MK(CK281-315), exhibited significant enzymatic 
      activity in the absence of Ca(2+)/CaM. In contrast, both MK and a chimeric 
      protein in which the C-terminal half of the autoregulatory domain of smMLCK was 
      replaced with CaM KII residues 301-315, MK(CK301-315), were inactive in the 
      absence of Ca(2+)/CaM. These results indicate that the sequence of the N-terminal 
      half of the autoregulatory domain of smMLCK is important for complete 
      autoinhibition of its enzymatic activity. All proteins bound to Ca(2+)/CaM, and 
      the chimeric proteins MK(CK281-478) and MK(CK281-315) were activated by 
      Ca(2+)/CaM with activation constants (K(CaM)) and maximal enzymatic activities 
      comparable to those of the wild-type MK enzyme. This demonstrates that the entire 
      autoregulatory domain of CaM KII can replace that of smMLCK in its ability to 
      promote efficient CaM-dependent activation of the smMLCK enzyme. However, the 
      inability of the chimeric protein MK(CK301-315) to be activated by Ca(2+)/CaM 
      suggests that replacement of only the C-terminal half of the autoregulatory 
      domain of smMLCK, while still retaining the ability to bind Ca(2+)/CaM, also 
      substitutes residues that prevent activation of the enzyme by Ca(2+)/CaM.
FAU - Chin, D
AU  - Chin D
AD  - Department of Pharmacology and Cancer Biology, Duke University Medical Center, 
      Durham, North Carolina 27710, USA.
FAU - Schreiber, J L
AU  - Schreiber JL
FAU - Means, A R
AU  - Means AR
LA  - eng
GR  - GM-33976/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Calmodulin)
RN  - 0 (Peptide Fragments)
RN  - 0 (Recombinant Fusion Proteins)
RN  - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinase Type 2)
RN  - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinases)
RN  - EC 2.7.11.18 (Myosin-Light-Chain Kinase)
SB  - IM
MH  - Animals
MH  - Calcium-Calmodulin-Dependent Protein Kinase Type 2
MH  - Calcium-Calmodulin-Dependent Protein Kinases/*chemistry/*genetics/metabolism
MH  - Calmodulin/*physiology
MH  - Chickens
MH  - Enzyme Activation/genetics
MH  - Muscle, Smooth/enzymology
MH  - Mutagenesis, Site-Directed
MH  - Myosin-Light-Chain Kinase/*antagonists & inhibitors/chemistry/genetics/metabolism
MH  - Peptide Fragments/genetics/metabolism
MH  - Phosphorylation
MH  - Recombinant Fusion Proteins/*chemistry/metabolism
MH  - Turkeys
EDAT- 1999/11/24 00:00
MHDA- 1999/11/24 00:01
CRDT- 1999/11/24 00:00
PHST- 1999/11/24 00:00 [pubmed]
PHST- 1999/11/24 00:01 [medline]
PHST- 1999/11/24 00:00 [entrez]
AID - bi990883a [pii]
AID - 10.1021/bi990883a [doi]
PST - ppublish
SO  - Biochemistry. 1999 Nov 16;38(46):15061-9. doi: 10.1021/bi990883a.