TRIM63

[6][7][8] This gene encodes a member of the RING zinc finger protein family found in striated muscle and iris.

The product of this gene is localized to the Z-line and M-line lattices of myofibrils, where titin's N-terminal and C-terminal regions respectively bind to the sarcomere.

Since these family members can form heterodimers, this suggests that these proteins may serve as a link between titin kinase and microtubule-dependent signal pathways in muscle.

[9] MuRF1 is upregulated during skeletal muscle atrophy – and thus the degradation of myosin heavy chain, which is a major component of the sarcomere, is an important mechanism in the breakdown of skeletal muscle under atrophy conditions [5] MuRF1 has been shown to be upregulated during denervation, administration of glucocorticoids, immobilization, and casting (when a cast is applied to a limb, in order to immobilize it).

This finding suggests that Myosin Heavy Chain levels may be dysregulated in the heart in the absence of MuRF1, leading to pathology.