Skip Navigation

Journal of Biochemistry 2005 137(3):407-413; doi:10.1093/jb/mvi051
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Chae, K. Y.
Right arrow Articles by Baek, K. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chae, K. Y.
Right arrow Articles by Baek, K. J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2005 The Japanese Biochemical Society

Regular Paper

Distinct pH Modulation for Dual Function of G{alpha}h (Transglutaminase II)

Kyu Young Chae1,*, Jin-Hee Kim1, Woo-Jae Park1, Yang-Gyun Kim1, Hye-Young Yun1, Nyoun Soo Kwon1, Mie-Jae Im2 and Kwang Jin Baek1,{dagger}

1 Department of Biochemistry, College of Medicine, Chung-Ang University, Seoul 156-756, Republic of Korea; and 2 Department of Biochemistry, School of Medicine, Chonbuk University, Chonju 790-784, Republic of Korea

{dagger} To whom correspondence should be addressed. Tel: +82-2-820-5654, Fax: +82-2-813-5387, E-mail: kjbaek{at}cau.ac.kr

ABSTRACT

G{alpha}h, also known as transglutaminase II, has GTPase as well as transglutaminase activities. To better understand the factors affecting these dual enzymatic activities, we examined the optimal pH (at 25°C) and thermal stability (at 37°C) of the activities using membranous G{alpha}h from mouse heart. The optimum pH for the GTPase activity of G{alpha}h is ~7.0. As well, the GTP binding activity of G{alpha}h is more thermostable at pH 7.0 than that at pH 9.0. Consistent with these observations on the GTPase function of G{alpha}h, both the phospholipase C-{delta}1 activity and the yield of co-immunoprecipitation of G{alpha}h-coupled phospholipase C-{delta}1 in {alpha}1-adrenoceptor/G{alpha}h/phospholipase C-{delta}1 complex preparations were enhanced by incubation with an {alpha}1-agonist, phenylephrine, at pH 7.0. On the other hand, the transglutaminase activity of G{alpha}h is higher in the basic pH range with an optimum activity at pH ~9.0. Also, the transglutaminase activity of G{alpha}h is more thermostable at pH 9.0 than that at pH 7.0. These results indicate not only pH as a modulator for the dual functions of G{alpha}h, but also provide direct evidence for the involvement of pH in the G{alpha}h-mediated {alpha}1-adrenoceptor signaling system in vitro.

FOOTNOTES

* Present address: Department of Pediatrics, College of Medicine, Pochon CHA University, Bundang CHA Hospital, Sungnam 463-712, Republic of Korea.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
H. H. von Horsten, S. S. Johnson, S. K. SanFrancisco, M. C. Hastert, S. M. Whelly, and G. A. Cornwall
Oligomerization and Transglutaminase Cross-linking of the Cystatin CRES in the Mouse Epididymal Lumen: POTENTIAL MECHANISM OF EXTRACELLULAR QUALITY CONTROL
J. Biol. Chem., November 9, 2007; 282(45): 32912 - 32923.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.