The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 

Processing of ADP-ribosylated integrin alpha 7 in skeletal muscle myotubes.

Integrin alpha 7 is a major substrate in skeletal muscle cells for the cell surface, glycosylphosphatidylinositol-anchored, arginine-specific ADP-ribosyltransferase. Since ADP-ribosylarginine hydrolase, the enzyme responsible for cleavage of the ADP-ribosylarginine bond and a component with the transferase of a putative ADP-ribosylation cycle, is cytosolic, the processing of ADP-ribosylated integrin alpha 7 was investigated. Following incubation of differentiated mouse C2C12 myoblasts with [adenylate-32P]NAD and analysis by SDS-polyacrylamide gel electrophoresis under reducing conditions, two [32P]ADP-ribosylated forms of integrin alpha 7 were resolved. By pulse-chase and purification of the radiolabeled proteins on a laminin affinity column, it was demonstrated that a 105-kDa ADP-ribosylated form originated from a mono-ADP-ribosylated 102-kDa form and represented integrin alpha 7 modified at more than one site. The additional site(s) of modification, utilized at higher NAD concentrations, were located in the 63-kDa N-terminal segment of integrin alpha 7. Both [32P]ADP-ribosylated integrins were loosely associated with the cytoskeleton, bound to laminin affinity columns, and immunoprecipitated with antibodies to integrin beta 1. 32P label was rapidly removed from [32P]ADP-ribosylated integrin alpha 7 at either site of modification, a process inhibited by free ADP-ribose or p-nitrophenylthymidine-5'-monophosphate, an alternative substrate of 5'-nucleotide phosphodiesterase. The processed integrin alpha 7 was unavailable for subsequent ADP-ribosylation, although the amount of surface integrin alpha 7 remained constant. During the processing, no loss of label was observed from integrin alpha 7 radiolabeled with [14C]NAD, containing 14C in the nicotinamide proximal ribose, consistent with degradation of the ADP-ribose moiety by a cell surface 5'-nucleotide phosphodiesterase. Thus, cell surface ADP-ribosylation, in contrast to intracellular ADP-ribosylation, is not readily reversed by ADP-ribosylarginine hydrolase and seems to operate outside the postulated ADP-ribosylation cycle.[1]

References

 
WikiGenes - Universities