BGLAP

BGLAP Full Name

bone gamma-carboxyglutamate (gla) protein

BGLAP Introduction

BGLAP, also known as bone gamma-carboxyglutamate protein or osteocalcin, is a small non-collagenous protein that is synthesized by osteoblasts during bone formation. BGLAP is vitamin K–dependent γ-carboxylated. The γ-carboxylation is required for high affinity binding to hydroxyapatite in the bone matrix. Osteocalcin is one of the most specific markers of bone turnover. BGLAP expression is tightly regulated by RUNX2, vitamin D, and mechanical loading.

Figure 1. Osteocalcin synthesis in osteoblasts.(Source: Aurora Patti, et al.; 2013)

Functionally, BGLAP is involved in the regulation of bone mineralization and matrix organization through its ability to bind to calcium and facilitate incorporation of mineral into the bone extracellular matrix. Uncarboxylated osteocalcin also functions as a hormone to regulate systemic physiology including insulin secretion and glucose metabolism, adiponectin production and cognitive function through endocrine release and signaling. As a result, BGLAP functions in both a structural capacity in bone and a hormonal capacity in peripheral tissues.

Clinically, changes in BGLAP activity are associated with metabolic and skeletal disease states. Low levels of osteocalcin are found in low bone turnover conditions. High levels of osteocalcin are found in high bone turnover states. Osteocalcin's endocrine actions have further implicated dysregulated BGLAP in insulin resistance, type 2 diabetes, obesity, and cardiovascular disease risk. Its presence in blood at measurable levels and well-characterized biology has made BGLAP a reliable bone metabolism biomarker and promising target for bone–metabolism crosstalk in disease.

Alternate Names for BGLAP

BGLAP; bone gamma-carboxyglutamate (gla) protein; OC; BGP; OCN; osteocalcin; bone Gla protein; gamma-carboxyglutamic acid-containing protein; bone gamma-carboxyglutamate (gla) protein (osteocalcin);

• 1. Aurora Patti, et al.; Endocrine Actions of Osteocalcin. International Journal of Endocrinology. 2013, (3):846480