The sensitive giant: the role of titin-based stretch sensing complexes in the heart.
Every heart beat is not equal. As physiological demands of the cardiovascular system change, cardiac myocytes modulate contractile parameters including the rate and force of contraction. Adaptive responses require the sensing of biomechanical signals involving the interface between the contractile cytoskeleton (myofibrils) and the sarcolemma at specialized cell-cell junctions (intercalated discs) and cell-substrate adhesion complexes (costameres). Recent studies have shed insight into how protein complexes within cardiac myocytes sense biomechanical signals, processes required for normal adaptive or pathological responses. This new evidence suggests that complexes associated with the giant, myofibrillar protein titin sense myocyte stretch. Here, we discuss evidence supporting titin being an ideal biomechanical sensor.
Miller
Melanie K
MK
Department of Cell Biology and Anatomy, The University of Arizona, Tucson, AZ 85724, USA.
Granzier
Henk
H
Ehler
Elisabeth
E
Gregorio
Carol C
CC
D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000378:metabolism / Q000473:pathology; D064211:Connectin; D006321:Heart / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D008954:Models, Biological; D009124:Muscle Proteins / Q000737:chemistry / Q000502:physiology*; D009200:Myocardial Contraction / Q000502:physiology*; D011494:Protein Kinases / Q000737:chemistry / Q000502:physiology*; D012518:Sarcomeres / Q000378:metabolism
D064211:Connectin; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases