학술논문
Less can be more – at least in mice: osteocalcin deficiency associated with increased bone formation
Document Type
Article
Author
Source
European Journal of Endocrinology; June 1997, Vol. 136 Issue: 6 p586-587, 2p
Subject
Language
ISSN
08044643; 1479683X
Abstract
Osteocalcin, a polypeptide composed of 49 amino acids, represents one of the most abundant non-collagenous proteins in bone tissue. In bone, osteocalcin is mainly synthesized by osteoblasts as they mature and become capable of mineralization (1). Of the three genes encoding osteocalcin, osteocalcin gene 1 (OG1) and 2 (OG2) are exclusively expressed in bone, whereas osteocalcin-related gene (ORG) is solely detected in the kidney (2). Various hormone-responsive elements for 1,25-dihydroxyvitamin D, retinoid acid analogues, glucocorticosteroids, thyroid hormone, cyclic AMP, as well as growth factors and cytokines have been located within the promoter region of osteocalcin, suggesting that osteocalcin gene expression is modulated by multiple factors (3,4). Proposed functions of osteocalcin include those of a bone adhesion molecule and chemotactic agent, a signal transducer, and a regulator of osteoclast differentiation, bone mineralization, and bone remodelling (5). Although several molecular and structural details of osteocalcin have been delineated during the last decade,