Identification of the dual specificity and the functional domains of the cardiac-specific protein kinase TNNI3K.
Molecular cloning of cardiac troponin I-interacting kinase (TNNI3K), a novel cardiac-specific protein kinase containing seven N-terminal ankyrin (ANK) repeats followed by a protein kinase domain and a C-terminal Ser-rich domain, has previously been reported. In the present study, we show that the C-terminal functional region of TNNI3K negatively regulates the kinase activity, and the N-terminal ANK domain is necessary for autophosphorylation. An in vitro kinase assay shows that TNNI3K exhibits dual-specific kinase activity and forms dimers or oligomers that may be necessary for its activation.
Feng
Y
Y
Department of Pathology, Medical College, Tongji University, Shanghai, PR China.
Cao
H Q
HQ
Liu
Z
Z
Ding
J F
JF
Meng
X M
XM
D020816:Amino Acid Motifs; D002461:Cell Line, Transformed; D003001:Cloning, Molecular; D019281:Dimerization; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000737:chemistry / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000201:enzymology; D010766:Phosphorylation; D055503:Protein Multimerization; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012694:Serine / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D012694:Serine; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C481078:TNNI3K protein, human; D020930:MAP Kinase Kinase Kinases