Agrin binds to the N-terminal region of Lrp4 protein and stimulates association between Lrp4 and the first immunoglobulin-like domain in muscle-specific kinase (MuSK).

Neuromuscular synapse formation depends upon coordinated interactions between motor neurons and muscle fibers, leading to the formation of a highly specialized postsynaptic membrane and a highly differentiated nerve terminal. Synapse formation begins as motor axons approach muscles that are prepatterned in the prospective synaptic region in a manner that depends upon Lrp4, a member of the LDL receptor family, and muscle-specific kinase (MuSK), a receptor tyrosine kinase. Motor axons supply Agrin, which binds Lrp4 and stimulates further MuSK phosphorylation, stabilizing nascent synapses.

Regulation of the intracellular localization of Foxo3a by stress-activated protein kinase signaling pathways in skeletal muscle cells.

Muscle atrophy is a debilitating process associated with many chronic wasting diseases, like cancer, diabetes, sepsis, and renal failure. Rapid loss of muscle mass occurs mainly through the activation of protein breakdown by the ubiquitin proteasome pathway. Foxo3a transcription factor is critical for muscle atrophy, since it activates the expression of ubiquitin ligase Atrogin-1.

Involvement of BTBD1 in mesenchymal differentiation.

BTBD1 is a recently cloned BTB-domain-containing protein particularly expressed in skeletal muscle and interacting with DNA topoisomerase 1 (Topo1), a key enzyme of cell survival. We have previously demonstrated that stable overexpression of a N-terminal truncated BTBD1 inhibited ex vivo myogenesis but not adipogenesis of pluripotent C2C12 cells. Here, BTBD1 expression was studied in three models of cellular differentiation: myogenesis (C2C12 cells), adipogenesis (3T3-L1 cells) and osteogenesis (hMADS cells).

Atrophy-related ubiquitin ligases, atrogin-1 and MuRF1 are up-regulated in aged rat Tibialis Anterior muscle.

A phenotypic feature of aging is skeletal muscle wasting. It is characterized by a loss of muscle mass and strength. Age-related loss of muscle mass occurs through a reduction in the rate of protein synthesis, an increase in protein degradation or a combination of both.

The p38 pathway regulates Akt both at the protein and transcriptional activation levels during myogenesis.

The molecular signalling pathways governing skeletal muscle differentiation remain unclear. Recent work has demonstrated that both the phosphatidylinositol 3-kinase (PI3K)/Akt and p38 pathways play important roles in myogenesis. Here, we describe the interactions between these pathways in C2C12 cells.