Analysis of the binding regions of SYT-SSX1 and hBRM/hSNF2α in 293T
cells. (A) SYT-SSX1 and its three deletion mutants (Fig.
2) expressed in 293T cells were immunoprecipitated with
anti-hBRM/hSNF2α antibody and probed with anti-SSX antibody
(Upper, lanes 1–4). Expression levels of SYT-SSX1 and
its mutants were examined by immunoblotting (Upper,
lanes 5–8). Immunoprecipitants and total cell lysates were also probed
with anti-hBRM antibody (Lower). Lysates with 200 μg
of proteins were used for immunoprecipitation and 20 μg of total cell
lysates were applied for immunoblotting. (B) 293T cell
lysates expressing SYT-SSX1 and its mutants were immunoprecipitated
with anti-SSX antibody and probed with anti-hBRM antibody
(Upper, lanes 1–4) or with anti-SSX antibody
(Lower, lanes 1–4). Protein expression levels of
endogenous hBRM/hSNF2α (Upper, lanes
5–8) and SYT-SSX1 and its mutants (Lower, lanes 5–8)
are displayed. (C) Association of hBRM/hSNF2α with N
terminus 181 amino acids of SYT. pcDNA3- HA-GFP-SYT-N181 was
transfected to 293T cells and total cell lysates were
immunoprecipitated with anti-BRM antibody (lane 1) or normal goat serum
(NGS; lane 2) and probed with anti-HA antibody. Expression levels of
SYT-N181 are shown in lane 3. Immunoprecipitants and total cell lysates
were also probed with anti-hBRM antibody (Lower).
(D) Schematic structure of hBRM/hSNF2α and its
mutants. The closed frame represents ATPase domain and the shaded frame
bromo domain. The number of amino acids comprising six mutants are
described. (E) Analysis of the binding region of
hBRM/hSNF2α to SYT-SSX1. Six mutants of hBRM were tagged with
HA-GFP, coexpressed with SYT-SSX1, and SYT-SSX1 was immunoprecipitated
by anti-SSX antibody and probed with anti-HA tag antibody to detect
coprecipitated mutants of hBRM/hSNF2α (Top).
Confirmations of expression levels of hBRM-derived mutants and SYT-SSX1
are shown in the Middle and Bottom. Lanes
1 to 6 correspond to the number of mutants described above. Lane 7,
HA-GFP; lane 8, empty vectors.