Titin: central player of hypertrophic signaling and sarcomeric protein quality control

The giant sarcomeric protein titin has mul- tiple important functions in striated muscle cells. Due to its gigantic size, its central position in the sarcomere and its elastic I-band domains, titin is a scaffold protein that is important for sarcomere assembly, and serves as a molecular spring that defines myofilament distensibility. This review focuses on the emerging role of titin in mecha- nosensing and hypertrophic signaling, and further high- lights recent evidence that links titin to sarcomeric protein turnover.