Recombinant Rat Fuctinin-3
Description
Molecular Characterization of α-Actinin-3
α-Actinin-3 is a Z-disc protein expressed predominantly in fast-twitch skeletal muscle fibers. It stabilizes actin filaments and regulates sarcomeric integrity, muscle contraction, and metabolic properties . The ACTN3 gene is highly conserved, with a common R577X polymorphism (rs1815739) causing a premature stop codon in ~16% of humans, resulting in α-actinin-3 deficiency .
Recombinant α-Actinin-3 in Experimental Models
Recombinant α-actinin-3 has been studied using overexpression systems in mice to investigate its functional roles:
Table 1: Functional Effects of Recombinant α-Actinin-3 in Mouse Models
*Data from . WT = wild-type; KO = knockout; *P < 0.01 vs. WT; *P < 0.01 vs. WT.
Mechanistic Insights from Recombinant Studies
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Dexamethasone Response: Actn3-KO mice show attenuated muscle atrophy under glucocorticoid treatment, with reduced expression of E3 ubiquitin ligases (Fbxo32, Trim63) and myostatin (Mstn) .
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Metabolic Shift: α-Actinin-3 deficiency increases oxidative metabolism and upregulates α-actinin-2, altering Z-disc composition .
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Gene Doping: Intramuscular delivery of rAAV-CMV-ACTN3 in WT mice failed to enhance force generation despite high vector doses (1E11 vg) .
Table 2: Recombinant Rat Protein Production Standards
| Protein | Source | Purity | Applications | Key Findings |
|---|---|---|---|---|
| α-Synuclein | E. coli | >95% | Fibril formation assays | Forms β-sheet structures |
| IFN-γ | Mammalian cells | ≥95% | Immune response modulation | Upregulates MHC class I/II |
Challenges and Future Directions
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Expression Limitations: Recombinant α-actinin-3 shows poor yield in bacterial systems, necessitating eukaryotic platforms (e.g., COS-7 cells) .
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Functional Redundancy: α-Actinin-2 compensates for α-actinin-3 loss, masking phenotypic effects in heterozygous models .
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Therapeutic Potential: ACTN3 gene therapy remains experimental, with no efficacy demonstrated in enhancing muscle performance .
