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FB2026_01
,
released March 12, 2026
This report describes a model of cardiac arrhythmia using the fly gene eas, which is orthologous to the ETNK1 and ETNK2 ethanolamine kinase genes in human. Ethanolamine kinase functions in the first step of the synthesis of phosphatidylethanolamine, the second-most abundant phospholipid in mammalian cells. Classical amorphic and loss-of-function alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated for Dmel\eas.
A UAS construct of the wild-type human Hsap\ETNK2 gene has been introduced into flies, but has not been characterized. The ETNK1 gene has not been introduced into flies. To date, neither human gene has been reported to be implicated in a cardiac arrhythmia disorder by OMIM.
Animals homozygous for a loss-of-function allele of Dmel\eas display tachycardia and defects in cardiac relaxation; they are prone to developing cardiac arrest and fibrillation under stress. The hearts of mutant animals exhibit elevated concentrations of triglycerides. Dmel\eas mutant adults also exhibit seizure sensitivity and abnormalities in the mushroom body lobes of the brain. A large number of genetic interactions have been described for this gene; see the gene report for eas.
See also the human disease model report 'seizure-sensitive (postulated), ETNK-related' (FBhh0000313).
[updated Apr. 2020 by FlyBase; FBrf0222196]
The term "arrhythmia" refers to any change from the normal sequence of electrical impulses in the heart, such as atrial fibrillation, bradycardia (slow heartbeat), tachycardia (rapid heart rate), conduction disorders, rhythm disorders, ventricular fibrillation, premature contractions. Arrhythmias may be completely harmless or life-threatening. (http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/About-Arrhythmia_UCM_002010_Article.jsp)
ETNK1 encodes an ethanolamine kinase which functions in the first committed step of the phosphatidylethanolamine synthesis pathway; this may be a rate-controlling step in phosphatidylethanolamine biosynthesis. ETNK2 is a member of the same ethanolamine kinase family. [Gene Cards, ETNK1, ETNK2; 2018.02.17]
Phosphatidylethanolamine (PE) is the second most abundant phospholipid in mammalian cells. PE comprises about 15-25% of the total lipid in mammalian cells; it is enriched in the inner leaflet of membranes, and it is especially abundant in the inner mitochondrial membrane. (Patel and Witt, 2017; pubmed:28785375)
Many to one: 2 human to 1 Drosophila; the fly gene eas is orthologous to ETNK1 and ETNK2 in human.
Many to one: 2 human to 1 Drosophila; the fly gene eas is orthologous to ETNK1 and ETNK2 in human.
High-scoring ortholog of human gene ETNK1 and moderate-scoring ortholog of ETNK2 (1 Drosophila to 2 human). Dmel\eas shares 35-39% identity and 49-52% similarity with the human genes.