LEPTIN, HUMAN

Structure

Leptin is produced as a 167-aa residue preprohormone, including an N-terminal 21-aa signal peptide, and is released as a 146-aa peptide after enzymatic cleavage.

Properties

Human leptin: Mr 16,000, pI 5.8. Leptin is soluble in water.

Uses

Leptin analogs are used for the treatment of lipodystrophy in clinical settings.

Gene, mRNA, and precursor

The human leptin gene, LEP, location 7q31.3, consists of three exons. Human leptin mRNA has a 3.5kb length that encodes a signal peptide of 21 aa residues and a mature protein of 146 aa residues.

Regulation of synthesis and release

The synthesis and release of leptin are regulated by environmental factors. In humans and rodents, obesity stimulates leptin synthesis and increases the plasma concentrations. Exercise decreases the plasma leptin concentrations in the rat. Exposure to low temperature suppresses leptin gene expression in WAT and reduces the plasma leptin concentrations in rodents. While fasting attenuates leptin gene expression, feeding restores the levels of gene expression.

Description

Leptin is an adipocyte hormone secreted from white adipose tissues that regulates energy expenditure and food intake by acting on receptors located in the hypothalamus.