Canine ventricular KCNE2 expression resides predominantly in Purkinje fibers.
Mutations in minK-related peptide 1 (MiRP1), the product of the KCNE2 gene, have been associated with malignant ventricular arrhythmia syndromes related to impaired repolarization. MiRP1 interacts with a variety of ion-channel alpha-subunits, dysfunction of which could account for arrhythmia syndromes; however, the observation of very low-level expression of MiRP1 in ventricular tissue has led to doubts about its relevance. The specialized His-Purkinje system plays a key role in cardiac electrophysiology and is an important contributor to ventricular arrhythmias related to abnormal repolarization. We examined the relative abundance of MiRP1 in canine Purkinje versus ventricular tissue and found much greater expression at both mRNA and protein levels in Purkinje tissue. Thus, the cardiac Purkinje system is a strong candidate to play a role in arrhythmic syndromes due to MiRP1 abnormalities.
Pourrier
Marc
M
Department of Medicine, .), University of Montreal, Montreal, Quebec, Canada.
Zicha
Stephen
S
Ehrlich
Joachim
J
Han
Wei
W
Nattel
Stanley
S
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000235:genetics; D015153:Blotting, Western; D016466:CHO Cells; D006224:Cricetinae; D004285:Dogs; D006352:Heart Ventricles / Q000378:metabolism*; D008133:Long QT Syndrome / Q000235:genetics; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D015221:Potassium Channels / Q000096:biosynthesis* / Q000235:genetics; D024642:Potassium Channels, Voltage-Gated; D011690:Purkinje Fibers / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012849:Sinoatrial Node / Q000378:metabolism; D014162:Transfection
D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; C059983:potassium channel protein I(sk)