FIG. 6.

IKK preferentially phosphorylates p105 complexed with M1-TPL-2. BMDMs (BALB/c) were simulated with LPS for the indicated times. (A) Total cell lysates or cell lysates depleted of p105 were subjected to Western blotting for TPL-2. Bands were quantified by densitometry, and data are presented as a mean (± SEM; n = 4) of the fraction of M1- or M30-TPL-2 that is released from p105 normalized against α-tubulin levels. (B) Total p105 or p105 phosphorylated on S927 was immunoprecipitated from total cell lysates by using anti-p105N or anti-phospho-S927-p105 antibodies, respectively. Associated TPL-2 was detected by Western blotting after SDS-PAGE.