Figure 6
Schematic representation of the interconversion of complexes observed and the intermediates characterised. Starting with the (Hsp90)2(Hop)1(Hsp70)1 complex, introduction of the immunophilins (FKBP51/52) leads to parallel reaction pathways in which the immunophilins are interchangeable and not required for the formation of these early complexes. Similarly three corresponding client-transfer complexes are formed when a second copy of Hsp70 and the GR client enter the reaction cycle. Interesting differences are observed when p23 is added to the client-transfer complex in the absence of the immunophilin or with FKBP51, two copies of p23 are incorporated with concomitant loss of Hsp70 and Hop. By contrast no stable complex with two p23 subunits is observed in the presence of FKBP52; expulsion of Hsp70, Hop and p23 occur with a low population of a complex incorporating only one p23 subunit. This central pathway leads to formation of the productive nuclear transfer complex, which is highly dynamic and primed for interaction with dynactin.
