Related Experiment Video
Updated: Jul 10, 2026

Aip1p Dynamics Are Altered by the R256H Mutation in Actin
Published on: July 30, 2014
Mutations in smooth muscle alpha-actin (ACTA2) lead to thoracic aortic aneurysms and dissections
Dong-Chuan Guo1, Hariyadarshi Pannu, Van Tran-Fadulu
1Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA.
Abstract:
The major function of vascular smooth muscle cells (SMCs) is contraction to regulate blood pressure and flow. SMC contractile force requires cyclic interactions between SMC alpha-actin (encoded by ACTA2) and the beta-myosin heavy chain (encoded by MYH11). Here we show that missense mutations in ACTA2 are responsible for 14% of inherited ascending thoracic aortic aneurysms and dissections (TAAD). Structural analyses and immunofluorescence of actin filaments in SMCs derived from individuals heterozygous for ACTA2 mutations illustrate that these mutations interfere with actin filament assembly and are predicted to decrease SMC contraction. Aortic tissues from affected individuals showed aortic medial degeneration, focal areas of medial SMC hyperplasia and disarray, and stenotic arteries in the vasa vasorum due to medial SMC proliferation. These data, along with the previously reported MYH11 mutations causing familial TAAD, indicate the importance of SMC contraction in maintaining the structural integrity of the ascending aorta.
More Related Videos
Related Concept Videos
Aneurysm I: Introduction
Aneurysm II: Clinical Manifestations and Diagnostic Studies
Actin Polymerization and Cell Motility
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Atherosclerosis I: Introduction
Introduction to Actin
Cardiomyopathy III: Hypertrophic Cardiomyopathy

