CT795 is enriched in the cytosolic fraction of chlamydia-infected HeLa cells. HeLa cells infected with C. trachomatis organisms (Ct-HeLa) were fractionated into nuclear (Ct-HeLa pellet, containing chlamydial inclusions; lane 3) and cytosolic (Ct-HeLa S100, containing chlamydia-secreted proteins; lane 4) portions. The cellular fractions along with total cell lysates (normal HeLa, lane 1, and Ct-HeLa, lane 2) and purified chlamydial RB (lane 5) and EB (lane 6) organisms, as listed at the top, were resolved on SDS-polyacrylamide gels. The resolved protein bands were blotted onto nitrocellulose membranes for reacting with antibodies (listed on the left) against CT795 (a), CPAF (b), CT813 (c; an inclusion membrane protein), MOMP (d), and human HSP70 (e). All antibodies detected their corresponding proteins in the HeLa-L2 whole-cell lysate sample (lane 2) and other corresponding samples (as indicated on the right). Note that both CT795 and CPAF were highly enriched in the cytosolic fraction (lane 4 in panels a and b) without any significant association with the purified organisms (lanes 5 and 6 in panels a and b).