TY - JOUR
T1 - Organization of the genetic locus for chicken myosin light chain kinase is complex
T2 - Multiple proteins are encoded and exhibit differential expression and localization
AU - Birukov, Konstantin G.
AU - Schavocky, James P.
AU - Shirinsky, Vladimir P.
AU - Chibalina, Margarita V.
AU - Van Eldik, Linda J.
AU - Watterson, D. Martin
PY - 1998/9/1
Y1 - 1998/9/1
N2 - We report that the genetic locus that encodes vertebrate smooth muscle and nonmuscle myosin light chain kinase (MLCK) and kinase-related protein (KRP) has a complex arrangement and a complex pattern of expression. Three proteins are encoded by 31 exons that have only one variation, that of the first exon of KRP, and the genomic locus spans approximately 100 kb of DNA. The three proteins can differ in their relative abundance and localization among tissues and with development. MLCK is a calmodulin (CAM) regulated protein kinase that phosphorylates the light chain of myosin II. The chicken has two MLCK isoforms encoded by the MLCK/KRP locus. KRP does not bind CaM and is not a protein kinase. However, KRP binds to and regulates the structure of myosin II. Thus, KRP and MLCK have the same subcellular target, the myosin II molecular motor system. We examined the tissue and cellular localization of KRP and MLCK in the chicken embryo and in adult chicken tissues. We report on the selective localization of KRP and MLCK among and within tissues and on a differential distribution of the proteins between embryonic and adult tissues. The results fill a void in our knowledge about the organization of the MLCK/KRP genetic locus, which appears to be a late evolving regulatory paradigm, and suggest an independent and complex regulation of expression of the gene products from the MLCK/KRP genetic locus that may reflect a basic principle found in other eukaryotic gene clusters that encode functionally linked proteins.
AB - We report that the genetic locus that encodes vertebrate smooth muscle and nonmuscle myosin light chain kinase (MLCK) and kinase-related protein (KRP) has a complex arrangement and a complex pattern of expression. Three proteins are encoded by 31 exons that have only one variation, that of the first exon of KRP, and the genomic locus spans approximately 100 kb of DNA. The three proteins can differ in their relative abundance and localization among tissues and with development. MLCK is a calmodulin (CAM) regulated protein kinase that phosphorylates the light chain of myosin II. The chicken has two MLCK isoforms encoded by the MLCK/KRP locus. KRP does not bind CaM and is not a protein kinase. However, KRP binds to and regulates the structure of myosin II. Thus, KRP and MLCK have the same subcellular target, the myosin II molecular motor system. We examined the tissue and cellular localization of KRP and MLCK in the chicken embryo and in adult chicken tissues. We report on the selective localization of KRP and MLCK among and within tissues and on a differential distribution of the proteins between embryonic and adult tissues. The results fill a void in our knowledge about the organization of the MLCK/KRP genetic locus, which appears to be a late evolving regulatory paradigm, and suggest an independent and complex regulation of expression of the gene products from the MLCK/KRP genetic locus that may reflect a basic principle found in other eukaryotic gene clusters that encode functionally linked proteins.
KW - Calcium
KW - Calmodulin
KW - Development
KW - Genome
KW - Heart
KW - Immunohistochemistry
KW - Protein kinase
KW - Signal transduction
KW - Smooth muscle
KW - Tissue selective
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U2 - 10.1002/(SICI)1097-4644(19980901)70:3<402::AID-JCB13>3.0.CO;2-M
DO - 10.1002/(SICI)1097-4644(19980901)70:3<402::AID-JCB13>3.0.CO;2-M
M3 - Article
C2 - 9706877
AN - SCOPUS:0031904240
SN - 0730-2312
VL - 70
SP - 402
EP - 413
JO - Journal of Cellular Biochemistry
JF - Journal of Cellular Biochemistry
IS - 3
ER -