The ubiquitous nature of the progesterone receptor binding factor-1 (RBF-1) in avian tissues.
The avian oviduct receptor binding factor-1 (RBF-1) is a 10 kDa nuclear matrix protein that was originally identified through its ability to effect high affinity interaction of activated progesterone receptor (PR) with chromatin. In the present study, the RBF-1 is shown to not be restricted to reproductive tissues (e.g., oviduct) but present in all avian tissues examined by Western blot analysis with a monoclonal antibody prepared against purified RBF-1. The heart and pancreas had the highest and lowest RBF-1 levels, respectively; the concentration ranging by approximately 50-fold in these tissues. The 10 kDa size of the RBF-1 detected in all tissues suggests no significant tissue-specific differences in the protein. This was consistent with the finding that purified hepatic and oviductal RBF-1 have identical amino-terminal sequence. Using a recently isolated cDNA to RBF-1, the levels of RBF-1 mRNA were found to correlate well with the ubiquitous presence of the protein as well as tissue-specific differences in concentration. The presence of RBF-1 in non-progesterone responsive tissues suggests the possibility that RBF-1 may not be specifically involved in PR-DNA interactions but may play a more diverse role, possibly involving other steroid receptors such as the glucocorticoid receptor.
Landers
J P
JP
Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, Minnesota 55905.
Subramaniam
M
M
Gosse
B
B
Weinshilboum
R
R
Madden
B J
BJ
Spelsberg
T C
TC
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D030161:Avian Proteins; D015153:Blotting, Western; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics; D002645:Chickens; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000737:chemistry; D008969:Molecular Sequence Data; D010057:Oviducts / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis; D011980:Receptors, Progesterone; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D030161:Avian Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C085646:RBF-1 protein, Gallus gallus; D012333:RNA, Messenger; D011980:Receptors, Progesterone