Detection of thymopoietin-responsive proteins in nude mouse spleen cells by two-dimensional polyacrylamide gel electrophoresis and image processing.
Lymphoid cells isolated from the spleen of BALB/c nu/nu nude mice were treated with synthetic human thymopoietin, and newly synthesized proteins were labeled by [35S]methionine incorporation. In the control experiment, the same lot of spleen cells were incubated in the labeling medium without the addition of thymopoietin. Urea/detergent-soluble proteins were extracted from the cells after 3 h incubation to be separated by two-dimensional poly-acrylamide gel electrophoresis. Spots of [35S]methionine-labeled proteins were visualized by autoradiography and analyzed by image processing. The computer-aided spot matching screened out three major thymopoietin-responsive proteins, TRP-1, -2 and -3. [35S]Methionine incorporation into TRP-3, of which the isoelectric point and molecular mass were approximately pI 5 and 10 kDa, respectively, was decreased by the thymopoietin treatment. In contrast with the down regulation, TRP-1, which was slightly higher in pI and slightly larger in molecular mass, and TRP-2, which was slightly higher in pI and almost the same in molecular mass as TRP-3, were evidently induced by the treatment. However, TRPs could not be assigned to Thy-1 antigen on the difference in molecular mass. The specific induction by the thymopoietin treatment suggested that TRP-1 and -2 might be novel proteins related to the intracellular signal transduction.
Toda
T
T
Department of Molecular Biology, Tokyo Metropolitan Institute of Gerontology, Japan.
Ishijima
Y
Y
Matsushita
H
H
Yoshida
M
M
Kimura
N
N
D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008819:Mice, Nude; D011506:Proteins / Q000032:analysis* / Q000187:drug effects; D013154:Spleen / Q000737:chemistry* / Q000166:cytology; D018800:Thy-1 Antigens / Q000096:biosynthesis; D013946:Thymopoietins / Q000494:pharmacology*
D011506:Proteins; D018800:Thy-1 Antigens; D013946:Thymopoietins