***************
Pharmacology & Toxicology Poster Session






Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References




Discussion
Board

INABIS '98 Home Page Your Session Symposia & Poster Sessions Plenary Sessions Exhibitors' Foyer Personal Itinerary New Search

Molecular Cloning and Characterization of Human PDE8 Isozymes of 3',5'-Cyclic Nucleotide Phosphodiesterase

Hayashi, M. (Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan)
Matsushima, K. (Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan)
Ohashi, H. (Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan)
Tsunoda, H. (Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan)
Murase, S. (Department of Medical Informatics, Mie University School of Medicine, Japan)
Kawarada, Y. (First Department of Surgery, Mie University School of Medicine, Japan)
Tanaka, T. (Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan)

Contact Person: Masaaki Hayashi (linlin@doc.medic.mie-u.ac.jp)


Abstract

Using a bioinformatic approach, we have identified two novel isozymes of human 3',5'-cyclic nucleotide phosphodiesterase (PDE), which we designated PDE8A and PDE8B. Both isozymes show 20 to 35% identity to the known human PDEs limited in the catalytic domain. The mRNA encoding PDE8A is expressed in a number of tissues and cancer cell lines and a smaller transcript was expressed specifically in the human colon rectal carcinoma cell SW480. On the contrary, the mRNA encoding PDE8B is expressed specifically and abundantly in thyroid gland. The carboxyl-terminal 584 amino acids of PDE8B were expressed in E.coli as a fusion protein. The recombinant PDE8B exhibited cAMP PDE activity which was not inhibited by various PDE inhibitors including vinpocetine, milrinone, rolipram, and IBMX with the exception of dipyridamole which caused 50% inhibition at a concentration of 40 ÁM. cAMP hydrolytic activity was unaffected by cGMP and no cGMP PDE hydrolysis were detectable at concentrations up to 100 ÁM. These findings suggest that these two isozymes are members of the new PDE family, PDE8.

Back to the top.
Poster Number PAhayashi0585
Keywords: phosphodiesterase, cyclic nucleotide


| Discussion Board | Next Page | Your Poster Session |
Hayashi, M.; Matsushima, K.; Ohashi, H.; Tsunoda, H.; Murase, S.; Kawarada, Y.; Tanaka, T.; (1998). Molecular Cloning and Characterization of Human PDE8 Isozymes of 3',5'-Cyclic Nucleotide Phosphodiesterase. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Available at URL http://www.mcmaster.ca/inabis98/pharmtox/hayashi0585/index.html
© 1998 Author(s) Hold Copyright