Nuclear localization of SYT, SSX and the synovial sarcoma-associated SYT-SSX fusion proteins.
Synovial sarcoma is characterized by a prevalent chromosomal translocation, t(X;18)(p11;q11). As a result of this translocation the SYT gene on chromosome 18 fuses to either the SSX1 or the SSX2 gene on the X chromosome. In this study, we generated polyclonal antibodies against the SYT and SSX2 proteins. These antibodies specifically detected both these proteins and the SYT-SSX fusion proteins in transfected COS-1 cell extracts. Indirect immunofluorescence analysis of COS-1 cells expressing tagged or untagged SYT, SSX2, SYT-SSX1 or SYT-SSX2 indicated that all these proteins are localized in the nucleus, excluding the nucleoli. The SSX2 protein exhibited a diffuse staining pattern whereas both the SYT and SYT-SSX proteins appeared in several nuclear dots. Similar nuclear dots were also detected in primary synovial sarcoma cells growing in a short-term in vitro culture. Double immunofluorescence in conjunction with confocal laser-scanning microscopy revealed that the SYT and SYT-SSX nuclear dots do not co-localize with known nuclear structures as e.g. coiled bodies, SC35 interchromatin granules or PML bodies. The similar nuclear localization patterns of SYT and SYT-SSX suggest that the SYT-SSX fusion proteins are directed to SYT-associated nuclear domains where an abnormal function may be exerted.
dos Santos
N R
NR
Department of Human Genetics, University Hospital Nijmegen, The Netherlands. n.dossantos@antrg.azn.nl
de Bruijn
D R
DR
Balemans
M
M
Janssen
B
B
Gärtner
F
F
Lopes
J M
JM
de Leeuw
B
B
Geurts van Kessel
A
A
D000328:Adult; D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D019556:COS Cells; D002467:Cell Nucleus / Q000276:immunology / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008297:Male; D009363:Neoplasm Proteins / Q000276:immunology / Q000378:metabolism*; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins / Q000276:immunology / Q000378:metabolism*; D013584:Sarcoma, Synovial / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000473:pathology
D009363:Neoplasm Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; C093961:SS18 protein, human; C093962:synovial sarcoma X breakpoint proteins