Table 2.
Summary of myofibril assembly and thin filament length phenotypes in Tmod1 perturbation experiments.
| Perturbation | Model system | Experimental strategy | Resulting phenotype | References |
|---|---|---|---|---|
| Reduced Tmod1 levels | Mouse embryonic heart | Gene knockout | Myofibril disorganization, nonstriated actin | [59, 65, 68] |
| Mouse embryonic stem cells | Gene knockout | Myofibril disorganization, nonstriated actin | [69] | |
| Mouse skeletal muscle | Gene knockout | No effect* | [31] | |
| Rat cardiomyocytes | Antisense cDNA expression | Thin filament elongation, nonstriated actin | [70] | |
| Drosophila primary muscle cells** | RNAi knockdown | Sarcomere length irregularity, thin filament elongation | [71] | |
| C. elegans body wall muscle*** | RNAi knockdown, unc94/tmd-1 mutant alleles | Myofibril disorganization, nonstriated actin, myofibril attachment defects | [14, 15] | |
| Inhibition of Tmod1 function | Chick cardiomyocytes | Antibody inhibition of actin capping | Thin filament elongation, nonstriated actin | [28] |
| Chick cardiomyocytes | Antibody inhibition of TM binding | Thin filament disassembly | [41] | |
| Tmod1 overexpression | Chick cardiomyocytes | cDNA expression | Thin filament shortening | [29] |
| Rat cardiomyocytes | cDNA expression | Myofibril disorganization, thin filament shortening | [70] | |
| Adult mouse heart | α-Myosin heavy chain promoter-driven Tmod1 transgene | Myofibril disorganization, thin filament shortening, intercalated disc defects | [72] | |
| Drosophila indirect flight muscle** | HSP-90-driven Tmod transgene | Thin filament shortening | [13] | |
| Drosophila primary muscle cells** | Dmef-GAL4, UAS-Tmod transgene | Thin filament shortening | [71] | |
*No myofibril assembly or thin filament length alterations occur in Tmod1-null mouse skeletal muscle, but extrasarcomeric SR defects do occur due to Tmod3 translocation from the SR to the thin filament pointed ends.
**Drosophila Tmod was knocked down or overexpressed.
***C. elegans UNC94/TMD-1 was knocked down or overexpressed.