Enhanced GRK5 expression in the hearts of cardiomyopathic hamsters, J2N-k.
GTP binding protein-coupled receptor kinase 5 (GRK5) cDNA was cloned from the hearts of Syrian hamsters. The hamster GRK5 cDNA contained 1770 nucleotides encoding 590 amino acids, and the nucleotide sequence had 89.6% homology to the human homologue. An inbred cardiomyopathic hamster strain, J2N-k, was used to investigate the alteration of GRK5 mRNA expression in the setting of congestive heart failure. M-mode echocardiography revealed significant dilatation of the left ventricle and a decrease of left ventricular contractility in 20-week-old J2N-k hamsters compared with age-matched control hamsters, J2N-n. Semi-quantitative RT-PCR showed that GRK5 mRNA expression in the hearts of J2N-k was significantly higher than in those of J2N-n (J2N-k 60.3 +/- 13.3, J2N-n 25.8 +/- 17.2 arbitrary units, p < 0.005, n = 6 in each group). These results suggest that an enhanced GRK5 expression might play a role in the reduced responsiveness to catecholamines in failing hearts via beta-adrenergic receptor phosphorylation.
Takagi
C
C
Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Sapporo, 060, Japan.
Urasawa
K
K
Yoshida
I
I
Takagi
Y
Y
Kaneta
S
S
Nakano
N
N
Onozuka
H
H
Kitabatake
A
A
D000375:Aging; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D054774:G-Protein-Coupled Receptor Kinase 5; D015971:Gene Expression Regulation, Enzymologic; D006333:Heart Failure / Q000201:enzymology / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008647:Mesocricetus / Q000235:genetics*; D008969:Molecular Sequence Data; D009200:Myocardial Contraction; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D009929:Organ Size; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014463:Ultrasonography; D015854:Up-Regulation
D012333:RNA, Messenger; D020794:Receptor Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D054774:G-Protein-Coupled Receptor Kinase 5; C517898:GRK5 protein, human