Stabilization of hsp70 mRNA on prolonged cell exposure to hypertonicity

• Published in: Biochimica et biophysica acta Vol. 1592; no. 2; pp. 135 - 140
• Main Authors: Alfieri, Roberta R, Bonelli, Mara A, Petronini, Pier Giorgio, Borghetti, Angelo F
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 21.10.2002
• Subjects: 3T3 Cells; Amino Acid Transport System A - genetics; Animals; ATA2 mRNA; DNA-Binding Proteins - metabolism; Heat shock protein; Heat Shock Transcription Factors; HSP70 Heat-Shock Proteins - biosynthesis; HSP70 Heat-Shock Proteins - genetics; HSP70 Heat-Shock Proteins - metabolism; hsp70 mRNA; Hypertonicity; Mice; mRNA stabilization; Protein Biosynthesis; RNA, Messenger - analysis; RNA, Messenger - biosynthesis; RNA, Messenger - metabolism; Saline Solution, Hypertonic; Transcription Factors; Transcription, Genetic; Transfection; ATA2 mRNA; Hypertonicity; mRNA stabilization; hsp70 mRNA; Heat shock protein
• ISSN: 0167-4889; 0006-3002; 1879-2596
• DOI: 10.1016/S0167-4889(02)00291-4

Prolonged exposure of 3T3 cells to 0.5 osM hypertonic medium induced the accumulation of hsp70 mRNAs. This increase in mRNA levels required active protein synthesis. A weak and transient activation of heat shock factor 1 (HSF1) was noted, but it was temporally uncoupled to the accumulation of the hsp70 mRNAs. Nuclear run-on assay and transfection experiments showed that hsp70 gene transcription was not affected by hypertonicity. ActD chase experiments showed that during hypertonic treatment, degradation of hsp70 mRNAs was markedly reduced. This effect did not appear to be a general phenomenon since the increase in mRNA level of another gene induced by hypertonicity (ATA2 transporter) was scarcely due to RNA stabilization. These findings suggest that hypertonic treatment increases the production of hsp70 protein in 3T3 cells via a stabilization of its corresponding mRNA.