Complement protein C3 is a 187-kDa (1641-aa) protein that plays a key role in complement activation and immune responses. Its hydrolyzed form, C3(H2O), is responsible for the initiation of the activation of alternative complement pathway. Previous analyses using mAbs, anilinonaphthalenesulfonate dyes, and functional studies have suggested that C3 is conformationally different from C3(H2O). We h...

Most physiology comparisons of C3 and C4 plants are made under current or elevated concentrations of atmospheric CO2 which do not reflect the low CO2 environment under which C4 photosynthesis has evolved. Accordingly, photosynthetic nitrogen (PNUE) and water (PWUE) use efficiency, and the activity of the photosynthetic carboxylases [Rubisco and phosphoenolpyruvate carboxylase (PEPC)] and decarb...

INTRODUCTION Abnormal control of the complement alternative pathway (CAP) (factor H, factor I and membrane cofactor protein (MCP) deficiencies) is a well established risk factor for the occurrence of haemolytic uraemic syndrome (HUS). In some instances, HUS may be associated with an unusual glomerulonephritis with isolated C3 deposits (glomerulonephritis C3). We determined whether HUS and glome...

It is known that C3 is required for optimal expansion of T cells during acute viral infections. However, it is not yet determined whether T cell responses to intracellular bacterial infections require C3. Therefore, we have investigated the requirement for C3 to elicit potent T cell responses to Listeria monocytogenes (LM). We show that expansion of Ag-specific CD8 and CD4 T cells during a prim...

In this study we have shown that complement component C3 is expressed in the regenerating tissue during urodele limb regeneration. C3 was expressed in the dedifferentiated regeneration blastema and in the redifferentiated limb tissues in the axolotl, Amblystoma mexicanum, and in Notophthalmus viridescens. This expression was verified by immunofluorescent staining using an Ab against axolotl C3 ...

We examined production of ADP-ribosyltransferase C3 in 11 strains of Clostridium botldinum type C and D and their nontoxigenic derivatives. Antisera to C3 proteins of type C organisms divided C3 proteins roughly into at least two groups, bearing no relation to their bacterial types. The C3 gene of type D strain South African was isolated from a toxigenic phage library, and the complete sequence...

C3 exoenzyme from Clostridium botulinum is the prototype of bacterial ADP-ribosyltransferases, which selectively modifies the Rho isoforms RhoA, RhoB and RhoC by covalent attachment of an ADP-ribose moiety. ADPribosylation results in inactivation of cellular functions of Rho. Because of its highly restricted substrate specificity, C3 is an established tool in cell biology; to this end C3 is app...

The theory for measuring ligand binding constants from footprinting autoradiographic data associated with a single binding site is derived. If the ligand and DNA cleavage agent compete for a common site, the spot intensities are not proportional to the amount of DNA not blocked by ligand. The analysis of a single site is experimentally illustrated by using results for the anticancer drug actino...

C3 exoenzyme is a mono-ADPribosyltransferase (ART) that catalyzes transfer of an ADP-ribose moiety from NAD to Rho GTPases. C3 has long been used to study the diverse regulatory functions of Rho GTPases. How C3 recognizes its substrate and ADP-ribosylation proceeds are still poorly understood. Crystal structures of C3-RhoA complex reveal that C3 recognizes RhoA via switch I, switch II and inter...