Fig. 6.

Integrins and other cell surface proteins as substrates for the ART2.1 expressed in lymphoid and myeloid leukocytes. a Major ADP-ribosylation targets for ART2.1 in freshly isolated spleen B and T cells versus IFN-γ (100 u/ml; 24 h) primed cultures of BMDM and BMDC (normalized for identical protein content (40 μg) per lane). Thiol-dependent ecto-ART activity was assayed as described in Fig. 4c. Results are representative of three independent experiments. b Effect of exogenous ADP-ribose on the relative accumulation of ADP-ribosylated proteins in freshly isolated spleen B and T cells versus IFN-γ (100 u/ml; 24 h) primed cultures of BMDM. c BALB/c BMDM were primed without or with 100 ng/ml LPS and 10 μg/ml U0126 for 24 h and then incubated for 15 min with 50 μM ε-NAD, 1 mM ADP-ribose (ADP-R), and 2 mM DTT. The cells were then lysed and processed for immunoprecipitation with anti-LFA or irrelevant IgG as described in the “Materials and methods” section. ADP-ribosylated proteins in the IPs were detected by probing the Western blot with 1G4 mAb. Results are representative of two experiments