Function of ubiquitin-like domain of chicken 2'-5'-oligoadenylate synthetase in conformational stability.
J Interferon Cytokine Res
; 23(11): 667-76, 2003 Nov.
Article
de En
| MEDLINE
| ID: mdl-14651781
ABSTRACT
2'-5'-Oligoadenylate synthetase (OAS), an interferon (IFN) induced enzyme, synthesizes 2'-5'-oligoadenylate (2-5A) from ATP when activated by dsRNA. Chicken OAS (ChOAS) has a ubiquitin-like (UbL) domain of two consecutive sequences (UbL1 and UbL2) at its carboxyl-terminus. The OAS gene has at least two alleles, OAS*A and OAS*B. OAS-A is the wild-type (wt) and OAS-B is a mutant deleted of a highly hydrophobic region of UbL1. To study the function of the UbL domain, enzymatic and physiologic properties were compared between OAS-A and OAS-B. OAS-B was more susceptible to trypsin than OAS-A and was converted very quickly into p38, deleting a greater part of the UbL domain. The p38 has the enzymatic activity to synthesize 2-5A. Thermal inactivation of OAS-B occurred at a lower temperature than that of OAS-A and p38, with loss of the ability to bind dsRNA. In contrast to OAS-A, the content of OAS-B in erythrocytes decreased during growth to a very low level. However, red blood cells (RBC) from anemic B/B chickens synthesized OAS-B at a high level comparable to A/A, although OAS-B levels decreased sharply again during maturation to erythrocytes. Thus, OAS-B carrying the mutated UbL domain is unstable compared with OAS-A in vitro and in vivo, and the wt UbL domain may contribute to the stability of the protein structure of ChOAS.
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Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Conformation des protéines
/
2',5'-Oligoadenylate synthetase
/
Ubiquitines
/
Allèles
Limites:
Animals
Langue:
En
Journal:
J Interferon Cytokine Res
Sujet du journal:
ALERGIA E IMUNOLOGIA
Année:
2003
Type de document:
Article
Pays d'affiliation:
Japon