Fos proteins are not prerequisite for osmotic induction of vasopressin transcription in supraoptic nucleus of rats.
While it is well known that osmotic stimulation induces the expression of Fos family members in the supraoptic nucleus (SON), it is unclear whether the induced protein products are involved in the regulation of the gene transcription of arginine vasopressin (AVP). In the present study, we examined the in vivo correlation between changes in AVP gene transcription and expression of the various Fos family members in the SON after acute osmotic stimuli. The data demonstrated that the peak of AVP transcription (measured by intronic in situ hybridization) observed 15min after an injection of hypertonic saline preceded the expression of Fos proteins, which became detectable at 30min and peaked at 120min. Electrophoretic mobility shift assay showed that the expressed Fos proteins bound to the composite AP-1/CRE-like site in the AVP promoter. These data suggest that Fos proteins in the SON induced by acute osmotic stimuli could affect AVP gene transcription by binding to the AVP promoter, but they are not prerequisite for the induction of AVP gene transcription.
Arima
Hiroshi
H
Section on Endocrine Physiology, Developmental Endocrinology Branch, National Institute of Child Health and Diseases, Bethesda, MD 20892, United States. arima105@med.nagoya-u.ac.jp
Baler
Ruben
R
Aguilera
Greti
G
D051698:Activating Transcription Factor 2 / Q000378:metabolism; D000818:Animals; D001127:Arginine Vasopressin / Q000096:biosynthesis*; D008297:Male; D009997:Osmotic Pressure; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D013495:Supraoptic Nucleus / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects*
D051698:Activating Transcription Factor 2; D016760:Proto-Oncogene Proteins c-fos; D012462:Saline Solution, Hypertonic; D018808:Transcription Factor AP-1; D001127:Arginine Vasopressin