Abstract

A REVIEW RATICAL: LEPTIN GENE AND OBESITY

Prof. Dr. Essam F. Al-Jumaily and Sara H. Zgaer

ABSTRACT

Leptin is an adipocytes-secreted hormone of mammals. It is a 167 amino acid protein hormone with important effects in regulating body weight and metabolism. Leptin is a cytokine hormone that is derived from the adipose tissue and expressed in the hypothalamus. Leptin or Obesity protein seems to play a role in regulating energy intake and expenditure. Leptin is a 16Kda protein coded by the obesity gene. The structure of Leptin is a proteins found in the helical cytokine family. It consists of four alpha helices that exhibit an up-up-down-down folding pattern arranged in a left-hand twisted bundle. Through activation of its receptor in the hypothalamus, leptin able to modulate energy expenditure and food intake when binding to the long leptin receptor isoform (LEPRb) activates cytokine like signal transduction via the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. In humans, leptin deficiency due to a mutation in the leptin gene is associated with early onset obesity.

Keywords: Leptin gene, leptin receptor gene, obesity