Activation of the C-fos promoter by increased internal pH

✍ Scribed by José R. Murguía; Luc De Vries; Lourdes Gomez-García; Axel Schönthal; Rosario Perona

• Book ID: 102878868
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 1008 KB
• Volume: 57
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240570407

✦ Synopsis

Changes in intracellular pH (pHin) take part in the mitogenic response. Their importance has been stressed by the finding that mouse fibroblasts expressing a yeast proton pumping ATPase (PMA?) exhibit a transformed phenotype and are tumorigenic. These cells do maintain a higher pHin, supporting the idea that elevated pHin may act as a proliferative trigger. Here we show that cells constitutively expressing PMA? have higher levels of the AP-1 transcription factor. The use of stable transfectants and transient transfection assays show that PMA? activity induces transactivation of the c-fos promoter. The activation of the promoter is mediated throughout the serum response element (SRE). The use of protein kinase C inhibitors suggests that AP-1 activation is achieved through a pathway independent of protein kinase C. a 1995 Wiley-Liss, Inc.