Electrophysiology data for NAA10-R4S-induced pluripotent-derived cardiomyocytes

N-terminal acetyltransferases including NAA10 catalyze N-terminal acetylation, an evolutionarily conserved co- and post-translational modification. However, little is known about the role of N-terminal acetylation in cardiac homeostasis. To gain insight into cardiac-dependent NAA10 function, we studied a previously unidentified NAA10 variant p.(Arg4Ser) segregating with QT-prolongation, cardiomyopathy, and developmental delay in a large kindred. Here, we show that the NAA10R4S variant reduced enzymatic activity, decreased NAA10-NAA15 complex formation, and destabilized the enzymatic complex N-terminal acetyltransferase A. In NAA10R4S/Y-induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs), dysregulation of the late sodium and slow delayed rectifier potassium currents caused severe repolarization abnormalities, consistent with clinical QT prolongation. Engineered heart tissues generated from NAA10R4S/Y-iPSC-CMs had significantly decreased contractile force and sarcomeric disorg..., Whole-cell patch clamp recordings
Cultured iPSC-CMs were dissociated with Accutase and plated sparsely onto Geltrex-coated 11mm coverslips. Single iPSC-CMs were analyzed 3 to 6 days after dissociating. Single iPSC-CMs were recorded under different conditions to acquire each parameter (Supplemental Table 1)50,51. Perforated patch recordings were performed for action potential (AP) analysis and the L-type Ca2+ current (ICaL). Perforated patch was applied in order to prevent run-down in ICaL recording52. The ruptured patch technique was used for INa, IKs, and IKr recordings. Series resistance and cell capacitance were compensated to ~ 60 % for all the voltage clamp experiments. To measure INa, starting from a holding potential of -100 mV, 40 ms of depolarizing pulses from -100 mV to 90 mV were applied in 10-mV increments. For the INa steady-state inactivation, following 400 ms of prepulses with 10-mV increments from -110 mV to -20 mV, 40 ms of 0 mV pulse was applied.  For IKs, test pu..., , # **Electrophysiology data for NAA10-R4S-induced pluripotent-derived cardiomyocytes**

[https://doi.org/10.5061/dryad.280gb5mvz](https://doi.org/10.5061/dryad.280gb5mvz)

The enclosed dataset contains electrophysiology data from patient-derived and genome-edited induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) with dysfunctional NAA10. Data includes multi-electrode array (MEA) recordings of monolayer cultures and patch-clamp electrophysiology of single cells.

### **Description of the data and file structure**

Files are in the GraphPad Prism format version 9 and version 10. Data is organized by related experiment and separated by patient-derived, genome-editing and wild type (WT) lines. All files are also uploaded in .csv format. Filenames are the same for both file formats. Any empty cells are replaced with “null” in the .csv files. These empty cells were left in the prism files to facilitate statistical calculations. 

Description of individual files and corresponding ...,