Spheroidin (SPH) is the most highly expressed gene of the entomopoxvirus isolated from Amsacta moorei (AmEPV). The level of expression of poxvirus genes is believed to be governed in large part by the promoter. Poxvirus promoters generally consist of approximately 40 bp which frequently terminate at the 3' end with a translation initiating TAAATG sequence. We have examined the requirements for ...

Although sphingomyelin (SPH) is a major constituent of all lipoproteins, its physiological function in plasma is not known. In this study, we tested the hypothesis that SPH inhibits lipid peroxidation in low density lipoproteins (LDL) because of its effects on surface fluidity and packing density and that the relative resistance of the buoyant LDL to oxidation, compared with the dense LDL, is p...

To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endoso...

The naturally occurring second messenger sphingosine (SPH) was examined for its ability to influence cardiac myocyte Ca2+ regulation. SPH inhibited intracellular Ca2+ transients in adult and neonatal rat ventricular myocytes. The inhibition was steeply dose dependent, with complete blockage of the Ca2+ transients occurring in the 20- to 25-mumol/L range. Whole-cell patch clamping revealed subst...

Clip domain serine proteinase homologs are involved in many biological processes including immune response. To identify the immune function of a serine proteinase homolog (Sp-SPH), originally isolated from hemocytes of the mud crab, Scylla paramamosain, the Sp-SPH was expressed recombinantly and purified for further studies. It was found that the Sp-SPH protein could bind to a number of bacteri...

Sphingomyelin derivatives exert various second messenger actions in numerous tissues. Sphingosine (SPH) and sphingosine 1-phosphate (S1P) are two major sphingomyelin derivatives present at high levels in blood. The aim of the present work was to investigate whether S1P and SPH exert relevant actions in mouse skeletal muscle contractility and fatigue. Exogenous S1P and SPH administration caused ...