Muscle cells, skeletal, translocation

Sweeney, G., Keen, J., Somwar, R., Konrad, D., Garg, R., and Klip, A. 2001. High leptin levels acutely inhibit insulin-stimulated glucose uptake without affecting glucose transporter 4 translocation in 16 rat skeletal muscle cells. Endocrinology 142 4806-4812. 

Calcium oxalate monohydrate responsible for the formation of most kidney stones significantly increased mitochondrial superoxide production in renal epithelial cells [42], Recombinant human interleukin IL-(3 induced oxygen radical generation in alveolar epithelial cells, which was suppressed by mitochondrial inhibitors 4 -hydroxy-3 -methoxyacetophe-none and diphenylene iodonium [43]. Espositio et al. [44] found that mitochondrial oxygen radical formation depended on the expression of adenine nucleotide translocator Anti. Correspondingly, mitochondria from skeletal muscle, heart, and brain from the Antl-deficient mice sharply increased the production of hydrogen peroxide. 

GLUT 4 translocation to the cell membrane in skeletal muscle is stimulated by exercise. This effect, which is independent of insulin, involves a 5 AMP-activated kinase. 

For each BoNT serotype, the dichain form constimtes the active configuration of the neurotoxin the isolated LC and HC are devoid of systemic toxicity. The absence of toxicity is consistent with findings that the LC cannot gain access to the cytosol unless it is coupled to the HC and that the HC lacks the ability to inhibit neurotransmitter release (Stecher et al., 1989 Goodnough et al., 2002). The isolated LC does, however, remain enzymatically active as evidenced by its ability to inhibit exocytosis from permeabilized chromaffin cells (Stecher et al., 1989), by its ability to cleave SNARE proteins in cell-free assays (Adler et al., 1998), and by its capacity to inhibit ACh release in skeletal muscle when delivered by liposomes (de Paiva and Dolly, 1990). It is not clear whether any portion of the HC is translocated along with the LC, and if so, whether it exerts a role in enhancing the catalytic activity or stability of the LC. 

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