Between Disease-Causing and an Innocent Bystander: The Role of Titin as a Modifier in Hypertrophic Cardiomyopathy  Brenda Gerull, MD  Canadian Journal of Cardiology  Volume 33, Issue 10, Pages 1217-1220 (October 2017) DOI: 10.1016/j.cjca.2017.07.010 Copyright © 2017 Canadian Cardiovascular Society Terms and Conditions

Figure 1 Titin domain structure and localization within the sarcomere. (A) Schematic depiction of the sarcomere. The titin filament is shown in red. One single molecule spans half of the sarcomere from the Z-disc to the M-line, as shown in (B). Each full sarcomere is covered by 2 adjacent titin molecules oriented in opposite directions. The thin (actin) filaments are shown in yellow; the thick (myosin) filaments with the myosin heads involved in cross-bridge formation are coloured in blue. (B) Schematic picture of the titin meta-transcript, which includes exons of all isoforms. The corresponding protein domains of a single titin molecule are indicated by different colours. (C) Exon usage according to Roberts et al.1 (http://cardiodb.org/titin). Exon usage describes the relative incorporation into transcripts expressed in cardiac tissue; 100% corresponds to an exon that is constitutively expressed whereas lower percentages indicate less exon usage and expression. Modified from Gerull et al.2 with permission from Elsevier. Canadian Journal of Cardiology 2017 33, 1217-1220DOI: (10.1016/j.cjca.2017.07.010) Copyright © 2017 Canadian Cardiovascular Society Terms and Conditions