The heart is the first organ required to function during embryonic development and is absolutely necessary for embryo survival. Cardiac activity is dependent on both the sinoatrial node (SAN), which is the pacemaker of heart's electrical activity, and the cardiac conduction system which transduces the electrical signal though the heart tissue, leading to heart muscle contractions. Defects in the development of cardiac electrical function may lead to severe heart disorders. The Erbb2 (Epidermal Growth Factor Receptor 2) gene encodes a member of the EGF receptor family of receptor tyrosine kinases. The Erbb2 receptor lacks ligand-binding activity but forms heterodimers with other EGF receptors, stabilising their ligand binding and enhancing kinase-mediated activation of downstream signalling pathways. Erbb2 is absolutely necessary in normal embryonic development and homozygous mouse knock-out Erbb2 embryos die at embryonic day (E)10.5 due to severe cardiac defects. We have isolated a mouse line, l11Jus8, from a random chemical mutagenesis screen, which carries a hypomorphic missense mutation in the Erbb2 gene. Homozygous mutant embryos exhibit embryonic lethality by E12.5-13. The l11Jus8 mutants display cardiac haemorrhage and a failure of atrial function due to defects in atrial electrical signal propagation, leading to an atrial-specific conduction block, which does not affect ventricular conduction. The l11Jus8 mutant phenotype is distinct from those reported for Erbb2 knockout mouse mutants. Thus, the l11Jus8 mouse reveals a novel function of Erbb2 during atrial conduction system development, which when disrupted causes death at mid-gestation.

Faculty of Life Sciences University of Manchester Manchester United Kingdom

Institute of Anatomy 1st Faculty of Medicine Charles University Prague and Institute of Physiology Academy of Sciences of the Czech Republic Prague Czech Republic

Syngenta Ltd Jeallots Hill United Kingdom

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Dobrzynski H, Boyett MR, Anderson RH (2007) New insights into pacemaker activity: promoting understanding of sick sinus syndrome. Circulation 115: 1921–1932. PubMed

Wolf CM, Berul CI (2006) Inherited conduction system abnormalities—one group of diseases, many genes. J Cardiovasc Electrophysiol 17: 446–455. PubMed

Harvey RP (2002) Patterning the vertebrate heart. Nat Rev Genet 3: 544–556. PubMed

Christoffels VM, Moorman AF (2009) Development of the cardiac conduction system: why are some regions of the heart more arrhythmogenic than others? Circ Arrhythm Electrophysiol 2: 195–207. PubMed

Christoffels VM, Smits GJ, Kispert A, Moorman AF (2010) Development of the pacemaker tissues of the heart. Circ Res 106: 240–254. PubMed

Lampe PD, Lau AF (2000) Regulation of gap junctions by phosphorylation of connexins. Arch Biochem Biophys 384: 205–215. PubMed

Lampe PD, Lau AF (2004) The effects of connexin phosphorylation on gap junctional communication. Int J Biochem Cell Biol 36: 1171–1186. PubMed PMC

Lodish H, Berk A, Matsudaira P, Kaiser CA, Krieger M, et al. (2004) Molecular Cell Biology. New York: W.H. Freeman and Company.

Alcolea S, Theveniau-Ruissy M, Jarry-Guichard T, Marics I, Tzouanacou E, et al. (1999) Downregulation of connexin 45 gene products during mouse heart development. Circ Res 84: 1365–1379. PubMed

Kumai M, Nishii K, Nakamura K, Takeda N, Suzuki M, et al. (2000) Loss of connexin45 causes a cushion defect in early cardiogenesis. Development 127: 3501–3512. PubMed

Severs NJ, Coppen SR, Dupont E, Yeh HI, Ko YS, et al. (2004) Gap junction alterations in human cardiac disease. Cardiovasc Res 62: 368–377. PubMed

Vaidya D, Tamaddon HS, Lo CW, Taffet SM, Delmar M, et al. (2001) Null mutation of connexin43 causes slow propagation of ventricular activation in the late stages of mouse embryonic development. Circ Res 88: 1196–1202. PubMed

Miquerol L, Moreno-Rascon N, Beyer S, Dupays L, Meilhac SM, et al. (2010) Biphasic development of the mammalian ventricular conduction system. Circ Res 107: 153–161. PubMed

van Kempen MJ, ten Velde I, Wessels A, Oosthoek PW, Gros D, et al. (1995) Differential connexin distribution accommodates cardiac function in different species. Microsc Res Tech 31: 420–436. PubMed

Salameh A, Blanke K, Daehnert I (2013) Role of connexins in human congenital heart disease: the chicken and egg problem. Front Pharmacol 4: 70. PubMed PMC

Holbro T, Hynes NE (2004) ErbB receptors: directing key signaling networks throughout life. Annu Rev Pharmacol Toxicol 44: 195–217. PubMed

Carraway KL 3rd, Cantley LC (1994) A neu acquaintance for erbB3 and erbB4: a role for receptor heterodimerization in growth signaling. Cell 78: 5–8. PubMed

Carraway KL 3rd, Sliwkowski MX, Akita R, Platko JV, Guy PM, et al. (1994) The erbB3 gene product is a receptor for heregulin. J Biol Chem 269: 14303–14306. PubMed

Tzahar E, Levkowitz G, Karunagaran D, Yi L, Peles E, et al. (1994) ErbB-3 and ErbB-4 function as the respective low and high affinity receptors of all Neu differentiation factor/heregulin isoforms. J Biol Chem 269: 25226–25233. PubMed

Olayioye MA (2001) Update on HER-2 as a target for cancer therapy: intracellular signaling pathways of ErbB2/HER-2 and family members. Breast Cancer Res 3: 385–389. PubMed PMC

Mohd Sharial MS, Crown J, Hennessy BT (2012) Overcoming resistance and restoring sensitivity to HER2-targeted therapies in breast cancer. Ann Oncol 23: 3007–3016. PubMed PMC

Lee KF, Simon H, Chen H, Bates B, Hung MC, et al. (1995) Requirement for neuregulin receptor erbB2 in neural and cardiac development. Nature 378: 394–398. PubMed

Negro A, Brar BK, Lee KF (2004) Essential roles of Her2/erbB2 in cardiac development and function. Recent Prog Horm Res 59: 1–12. PubMed

Ozcelik C, Erdmann B, Pilz B, Wettschureck N, Britsch S, et al. (2002) Conditional mutation of the ErbB2 (HER2) receptor in cardiomyocytes leads to dilated cardiomyopathy. Proc Natl Acad Sci U S A 99: 8880–8885. PubMed PMC

Erickson SL, O'Shea KS, Ghaboosi N, Loverro L, Frantz G, et al. (1997) ErbB3 is required for normal cerebellar and cardiac development: a comparison with ErbB2-and heregulin-deficient mice. Development 124: 4999–5011. PubMed

Garratt AN, Voiculescu O, Topilko P, Charnay P, Birchmeier C (2000) A dual role of erbB2 in myelination and in expansion of the schwann cell precursor pool. J Cell Biol 148: 1035–1046. PubMed PMC

Liu J, Bressan M, Hassel D, Huisken J, Staudt D, et al. (2010) A dual role for ErbB2 signaling in cardiac trabeculation. Development 137: 3867–3875. PubMed PMC

Kile BT, Hentges KE, Clark AT, Nakamura H, Salinger AP, et al. (2003) Functional genetic analysis of mouse chromosome 11. Nature 425: 81–86. PubMed

Hentges KE, Nakamura H, Furuta Y, Yu Y, Thompson DM, et al. (2006) Novel lethal mouse mutants produced in balancer chromosome screens. Gene Expr Patterns 6: 653–665. PubMed

Li H, Durbin R (2009) Fast and accurate short read alignment with Burrows-Wheeler transform. Bioinformatics 25: 1754–1760. PubMed PMC

Blankenberg D, Von Kuster G, Coraor N, Ananda G, Lazarus R, et al. (2010) Galaxy: a web-based genome analysis tool for experimentalists. Curr Protoc Mol Biol Chapter 19: Unit 19 10 11–21. PubMed PMC

Giardine B, Riemer C, Hardison RC, Burhans R, Elnitski L, et al. (2005) Galaxy: a platform for interactive large-scale genome analysis. Genome Res 15: 1451–1455. PubMed PMC

Goecks J, Nekrutenko A, Taylor J, Galaxy T (2010) Galaxy: a comprehensive approach for supporting accessible, reproducible, and transparent computational research in the life sciences. Genome Biol 11: R86. PubMed PMC

McLaren W, Pritchard B, Rios D, Chen Y, Flicek P, et al. (2010) Deriving the consequences of genomic variants with the Ensembl API and SNP Effect Predictor. Bioinformatics 26: 2069–2070. PubMed PMC

Thompson JD, Gibson TJ, Higgins DG (2002) Multiple sequence alignment using ClustalW and ClustalX. Curr Protoc Bioinformatics Chapter 2: Unit 2 3. PubMed

Sali A, Blundell TL (1993) Comparative protein modelling by satisfaction of spatial restraints. J Mol Biol 234: 779–815. PubMed

Ishikawa T, Seto M, Banno H, Kawakita Y, Oorui M, et al. (2011) Design and synthesis of novel human epidermal growth factor receptor 2 (HER2)/epidermal growth factor receptor (EGFR) dual inhibitors bearing a pyrrolo[3,2-d]pyrimidine scaffold. J Med Chem 54: 8030–8050. PubMed

Word JM, Lovell SC, Richardson JS, Richardson DC (1999) Asparagine and glutamine: using hydrogen atom contacts in the choice of side-chain amide orientation. J Mol Biol 285: 1735–1747. PubMed

Chen VB, Davis IW, Richardson DC (2009) KING (Kinemage, Next Generation): a versatile interactive molecular and scientific visualization program. Protein Sci 18: 2403–2409. PubMed PMC

Lovell SC, Word JM, Richardson JS, Richardson DC (2000) The penultimate rotamer library. Proteins 40: 389–408. PubMed

Word JM, Lovell SC, LaBean TH, Taylor HC, Zalis ME, et al. (1999) Visualizing and quantifying molecular goodness-of-fit: small-probe contact dots with explicit hydrogen atoms. J Mol Biol 285: 1711–1733. PubMed

Henrique D, Adam J, Myat A, Chitnis A, Lewis J, et al. (1995) Expression of a Delta homologue in prospective neurons in the chick. Nature 375: 787–790. PubMed

Sankova B, Benes J Jr, Krejci E, Dupays L, Theveniau-Ruissy M, et al. (2012) The effect of connexin40 deficiency on ventricular conduction system function during development. Cardiovasc Res 95: 469–479. PubMed

Reckova M, Rosengarten C, deAlmeida A, Stanley CP, Wessels A, et al. (2003) Hemodynamics is a key epigenetic factor in development of the cardiac conduction system. Circ Res 93: 77–85. PubMed

Sedmera D, Wessels A, Trusk TC, Thompson RP, Hewett KW, et al. (2006) Changes in activation sequence of embryonic chick atria correlate with developing myocardial architecture. Am J Physiol Heart Circ Physiol 291: H1646–1652. PubMed

Boles MK, Wilkinson BM, Wilming LG, Liu B, Probst FJ, et al. (2009) Discovery of candidate disease genes in ENU-induced mouse mutants by large-scale sequencing, including a splice-site mutation in nucleoredoxin. PLoS Genet 5: e1000759. PubMed PMC

Grainger RJ, Beggs JD (2005) Prp8 protein: at the heart of the spliceosome. RNA 11: 533–557. PubMed PMC

Camenisch TD, Schroeder JA, Bradley J, Klewer SE, McDonald JA (2002) Heart-valve mesenchyme formation is dependent on hyaluronan-augmented activation of ErbB2-ErbB3 receptors. Nat Med 8: 850–855. PubMed

Benes JJ, Ammirabile G, Sankova B, Campione M, Krejci E, et al. (2014) The role of connexin40 in developing atrial conduction. FEBS Letters In press. PubMed

Sedmera D, Reckova M, DeAlmeida A, Coppen SR, Kubalak SW, et al. (2003) Spatiotemporal pattern of commitment to slowed proliferation in the embryonic mouse heart indicates progressive differentiation of the cardiac conduction system. Anat Rec A Discov Mol Cell Evol Biol 274: 773–777. PubMed

Kirchhoff S, Kim JS, Hagendorff A, Thonnissen E, Kruger O, et al. (2000) Abnormal cardiac conduction and morphogenesis in connexin40 and connexin43 double-deficient mice. Circ Res 87: 399–405. PubMed

Abecasis GR, Auton A, Brooks LD, DePristo MA, Durbin RM, et al. (2012) An integrated map of genetic variation from 1,092 human genomes. Nature 491: 56–65. PubMed PMC

Kumar P, Henikoff S, Ng PC (2009) Predicting the effects of coding non-synonymous variants on protein function using the SIFT algorithm. Nat Protoc 4: 1073–1081. PubMed

Adzhubei IA, Schmidt S, Peshkin L, Ramensky VE, Gerasimova A, et al. (2010) A method and server for predicting damaging missense mutations. Nat Methods 7: 248–249. PubMed PMC

Pentassuglia L, Sawyer DB (2009) The role of Neuregulin-1beta/ErbB signaling in the heart. Exp Cell Res 315: 627–637. PubMed PMC

Fuller SJ, Sivarajah K, Sugden PH (2008) ErbB receptors, their ligands, and the consequences of their activation and inhibition in the myocardium. J Mol Cell Cardiol 44: 831–854. PubMed

Dankort DL, Wang Z, Blackmore V, Moran MF, Muller WJ (1997) Distinct tyrosine autophosphorylation sites negatively and positively modulate neu-mediated transformation. Mol Cell Biol 17: 5410–5425. PubMed PMC

Chan R, Hardy WR, Dankort D, Laing MA, Muller WJ (2004) Modulation of Erbb2 signaling during development: a threshold level of Erbb2 signaling is required for development. Development 131: 5551–5560. PubMed

Gassmann M, Casagranda F, Orioli D, Simon H, Lai C, et al. (1995) Aberrant neural and cardiac development in mice lacking the ErbB4 neuregulin receptor. Nature 378: 390–394. PubMed

Threadgill DW, Dlugosz AA, Hansen LA, Tennenbaum T, Lichti U, et al. (1995) Targeted disruption of mouse EGF receptor: effect of genetic background on mutant phenotype. Science 269: 230–234. PubMed

Sibilia M, Wagner EF (1995) Strain-dependent epithelial defects in mice lacking the EGF receptor. Science 269: 234–238. PubMed

Rentschler S, Zander J, Meyers K, France D, Levine R, et al. (2002) Neuregulin-1 promotes formation of the murine cardiac conduction system. Proc Natl Acad Sci U S A 99: 10464–10469. PubMed PMC

Kuramochi Y, Guo X, Sawyer DB (2006) Neuregulin activates erbB2-dependent src/FAK signaling and cytoskeletal remodeling in isolated adult rat cardiac myocytes. J Mol Cell Cardiol 41: 228–235. PubMed PMC

Britto JM, Lukehurst S, Weller R, Fraser C, Qiu Y, et al. (2004) Generation and characterization of neuregulin-2-deficient mice. Mol Cell Biol 24: 8221–8226. PubMed PMC

Crone SA, Zhao YY, Fan L, Gu Y, Minamisawa S, et al. (2002) ErbB2 is essential in the prevention of dilated cardiomyopathy. Nat Med 8: 459–465. PubMed

Doggen K, Ray L, Mathieu M, Mc Entee K, Lemmens K, et al. (2009) Ventricular ErbB2/ErbB4 activation and downstream signaling in pacing-induced heart failure. J Mol Cell Cardiol 46: 33–38. PubMed

Nielsen DL, Kumler I, Palshof JA, Andersson M (2013) Efficacy of HER2-targeted therapy in metastatic breast cancer. Monoclonal antibodies and tyrosine kinase inhibitors. Breast 22: 1–12. PubMed