ACTC1: ACTC, actin, alpha, cardiac muscle 1, smooth muscle actin

Gene Type: protein coding

General Information:

• Actin are very abundant types of proteins that exist the most in eukaryotic cells that participate in cell motility [R].

• ACTC1 exists in house mouses, Norway rats, chickens, tropical clawed frogs, cattle, African clawed frog, dogs, dolphins, sheep, domestic cats, and many more. But this summary of the gene will be based on Homo sapiens, humans.

• 3 groups of actin isoforms are associated with the protein encoded by ACTC1 [R]

  • Alpha

  • Beta

  • Gamma

• Some defects of ACTC1 are associated with idiopathic dilated cardiomyopathy (IDC) and familial hypertrophic cardiomyopathy (FHC) [R2].

  • IDC: This disease is actually called cardiomyopathy, but because its cause is can’t be determined for more than 50% of the time, the title idiopathic comes into play.

    • Some causes of IDC are genetics, congenital heart defects, exposure to toxins, hypertension, and diabetes [R3].  

  • FHC: A heart condition caused by thickening of heart muscle [https://ghr.nlm.nih.gov/condition/familial-hypertrophic-cardiomyopathy].  

Phenotype-Inheritance:

• Cardiomyopathy, dilated- autosomal dominant

  • No relationship between actin dysfunction leading to heart failure was found with Olsens’ examination of IDC patients with a mutation of ACTC gene. Some races or cultures showed only some families with the mutated gene to affect the skeletal/ cardiac actin genes [R4].

• Left ventricular noncompaction- autosomal dominant

• Cardiomyopathy, hypertrophic- autosomal dominant

• Atrial septal defect

Function/ Mutations:

• ACTC1 is a gene responsible for proteins in muscle cells.

• This gene is a predominant isoform in human donor hearts, as well as early skeletal muscle development [R5].

• The ACTC gene is found in skeletal muscles is also the same gene that makes ACTC mRNA in the heart [R5].

  • Mutations of this gene cause diseases like hypertrophic cardiomyopathy, and like others like stated above.

  • However, tests have concluded that lower levels of ACTC1 may lead to ASD (atrial septal defect) without showing particular signs of cardiomyopathy [R6].

ACTC mutations are also the case of atrial septal defects [R5].

The following transcription factors affect gene expression:

• p53
• Pax-3
• C/EBPalpha
• Sp1
• IRF-1
• IRF-2

Molecular Function:

• Atpase Activity
• Atp Binding
• Myosin Binding

Biological Processes:

• Actin Filament-Based Movement
• Actin-Myosin Filament Sliding
• Actomyosin Structure Organization
• Apoptotic Process
• Cardiac Muscle Contraction
• Cardiac Muscle Tissue Morphogenesis
• Cardiac Myofibril Assembly
• Heart Contraction
• Mesenchyme Migration
• Muscle Filament Sliding
• Negative Regulation Of Apoptotic Process
• Positive Regulation Of Gene Expression
• Response To Ethanol
• Skeletal Muscle Thin Filament Assembly