Title:Chaperones and Cardiac Misfolding Protein Diseases
VOLUME: 15 ISSUE: 3
Author(s):Elisabeth S. Christians, Soumyajit B. Mustafi and Ivor J. Benjamin
Affiliation:Department of Internal Medicine and Biochemistry, 30 N. 1900 E. Room 4A100, Salt Lake City, UT 84132, USA.
Keywords:Aggregates, amyloid, cardiomyocyte, heat shock factor, heat shock proteins, homeostasis, mouse models, mutation.
Abstract:Cardiomyocytes are best known for their spontaneous beating activity, large cell size, and low regenerative capacity
during adulthood. The mechanical activity of cardiomyocytes depends on a sophisticated contractile apparatus
comprised of sarcomeres whose rhythmic contraction relies on Ca2+ transients with a high level of energy consumption.
Hence the proper folding and assembly of the sarcomeric and other accessory proteins involved in those diverse functions
(i.e., structural, mechanical, energy exchange and production) is critical for muscle mechanics. Chaperone proteins assist
other polypeptides to reach their proper conformation, activity and/or location. Consequently, chaperone-like functions are
important for the healthy heart but assume greater relevance during cardiac diseases when such chaperone proteins are recruited:
1) to protect cardiac cells against adverse effects during the pathological transition, and 2) to mitigate certain
pathogenic mechanisms per se. Protein misfolding is observed as a consequence of inappropriate intracellular environment
with acquired conditions (e.g., ischemia/reperfusion and redox imbalance) or because of mutations, which can modify
primary to quaternary protein structures. In this review, we discuss the importance of cardiac chaperones while emphasizing
the genetic origin (modification of gene/protein sequence) of cardiac protein misfolding and their consequences on
the cardiomyocytes leading to organ dysfunction and failure.
