Heat shock induces intestinal-type alkaline phosphatase in rat IEC-18 cells.

Abstract

We demonstrate a previously unknown regulation for intestinal-type alkaline phosphatase (IAP) as a heat shock protein (HSP). Heat shock to rat intestinal epithelial cells (IEC)-18 at 43 degrees C induced the expression of IAP-I and HSP72 mRNAs time dependently (<60 min) but did not induce expression of IAP-II, tissue nonspecific-type alkaline phosphatase (TNAP), or HSP90 as determined by the RT-PCR method. To confirm the identity of the IAP-I gene, we sequenced the amplification product of IAP-I and found the gene to have 99% homology with the sequence of the IAP-I gene in rat intestine. Under the subculture conditions used, no IAP protein was detected in IEC-18 cells, but it became detectable as a 62-kDa band on a Western blot after heat shock. IAP-I was also induced by sodium arsenite, which generates reactive oxygen species and is an inducer of members of the HSP family. Glutathione suppressed activating protein-1 and cAMP response element-binding protein activation caused by heat shock but did not suppress the expression of IAP-I. These results suggest that cellular stress induces the elevation of IAP-I mRNA and protein synthesis. IAP-I may play an important role as a dephosphorylating enzyme under stress conditions.

• Authors: Tsuyoshi Harada, Iwao Koyama, Toshihiko Kasahara, David H Alpers, Tsugikazu Komoda
• Journal: American journal of physiology. Gastrointestinal and liver physiology (Am J Physiol Gastrointest Liver Physiol) Vol. 284 Issue 2 Pg. G255-62 (Feb 2003) ISSN: 0193-1857 [Print] United States
• PMID: 12388181 (Publication Type: Journal Article)

Chemical References

• Arsenites
• Cyclic AMP Response Element-Binding Protein
• Heat-Shock Proteins
• Isoenzymes
• RNA, Messenger
• Transcription Factors
• Dactinomycin
• Alkaline Phosphatase
• Glutathione
• arsenite

Topics

• Alkaline Phosphatase (chemistry, metabolism)
• Animals
• Arsenites (pharmacology)
• Base Sequence
• Blotting, Western
• Cell Line
• Cell Nucleus (genetics)
• Cyclic AMP Response Element-Binding Protein (metabolism)
• Dactinomycin (pharmacology)
• Glutathione (pharmacology)
• Heat-Shock Proteins (chemistry, metabolism)
• Hot Temperature
• Intestines (enzymology)
• Isoenzymes (chemistry, metabolism)
• Molecular Sequence Data
• RNA, Messenger (biosynthesis, genetics)
• Rats
• Reverse Transcriptase Polymerase Chain Reaction
• Transcription Factors (genetics)