E-resources
Peer reviewed
-
Turker, Isik; Makiyama, Takeru; Ueyama, Takeshi; Shimizu, Akihiko; Yamakawa, Masaru; Chen, Peng‐Sheng; Vatta, Matteo; Horie, Minoru; Ai, Tomohiko
Pacing and clinical electrophysiology, August 2020, Volume: 43, Issue: 8Journal Article
Background Telethonin (TCAP) is a Z‐disk protein that maintains cytoskeletal integrity and various signaling pathways in cardiomyocytes. TCAP is shown to modulate α‐subunit of the human cardiac sodium channel (hNav1.5) by direct interactions. Several TCAP variants are found in cardiomyopathies. We sought to investigate whether TCAP variants are associated with arrhythmia syndromes. Methods Mutational analyses for TCAP were performed in 303 Japanese patients with Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and J‐wave pattern ECG. Using patch‐clamp techniques, electrophysiological characteristics of hNav1.5 were studied in HEK‐293 cells stably expressing hNav1.5 and transiently transfected with wild‐type (WT) or variant TCAP. Results We identified two TCAP variants, c.145G>A:p.E49K and c.458G>A:p.R153H, in four individuals. p.E49K was found in two patients with ARVC or BrS. p.R153H was found in two patients with BrS or J‐wave pattern ECG. No patient had variant hNav1.5. Patch‐clamp experiments demonstrated that peak sodium currents were significantly reduced in cells expressing p.R153H and p.E49K compared with WT‐TCAP (66%, p.R153H; 72%, p.E49K). Voltage dependency of peak IV curve was rightward‐shifted by 5 mV in cells expressing p.E49K compared with WT‐TCAP. Voltage dependency of activation was not leftward‐shifted by p.R153H, while voltage dependency of steady‐state inactivation was leftward‐shifted by p.E49K. Conclusions We found two TCAP variants in the patients with BrS, J‐wave pattern ECG, and ARVC that can cause loss‐of‐function of the hNav1.5 in heterologous expression systems. Our observation suggests that these variants might impair INa and be associated with the patients’ electrophysiological phenotypes. Further studies linking our experimental data to clinical phenotypes are warranted.
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Shelf entry
Permalink
- URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year | Impact factor | Edition | Category | Classification | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Select the library membership card:
If the library membership card is not in the list,
add a new one.
DRS, in which the journal is indexed
Database name | Field | Year |
---|
Links to authors' personal bibliographies | Links to information on researchers in the SICRIS system |
---|
Source: Personal bibliographies
and: SICRIS
The material is available in full text. If you wish to order the material anyway, click the Continue button.