Zunaira salehabout 16 hours ago

An enzyme-linked receptor—the leptin receptor.

 The receptor exists as a homodimer (two identical parts), and leptin binds to the extracellular part of the receptor, causing phosphorylation (P) and activation of the intracellular associated janus kinase 2 (JAK2). This mechanism causes phosphorylation of signal transducer and activator of transcription (STAT) proteins, which then activates the transcription of target genes and the synthesis of proteins. JAK2 phosphorylation also activates several other enzyme systems that mediate some of the more rapid effects of leptin. Y, specific tyrosine phosphorylation sites.