Trim32 binds thin filament and Z-band components in the muscle homogenate
| Protein name | Gene | No. of unique peptides (found initially) | Precipitated from normal muscle with pure Trim32 | Ubiquitylated after the addition of E1, E2, and ATP |
| α-Actin | Acta1 | 5 | + | + |
| α-Actinin | Actn3 | 1 | + | + |
| Tropomyosin 1 alpha chain | Tpm1 | 1 | + | + |
| Desmin | Des | 1 | + | + |
| Myosin regulatory light chain | Mylpf | 1 | + |
| Protein name | Gene | No. of unique peptides (found initially) | Precipitated from normal muscle with pure Trim32 | Ubiquitylated after the addition of E1, E2, and ATP |
| α-Actin | Acta1 | 5 | + | + |
| α-Actinin | Actn3 | 1 | + | + |
| Tropomyosin 1 alpha chain | Tpm1 | 1 | + | + |
| Desmin | Des | 1 | + | + |
| Myosin regulatory light chain | Mylpf | 1 | + |
Trim32-bound proteins were precipitated together with Trim32 from the soluble fraction of TA and identified by mass spectrometry. When a subsequent in vitro ubiquitylation reaction was carried out, mass spectrometry analysis identified actin, α-actinin, Tm, and desmin as ubiquitylated species.