What is the Origin of Prolactin Signaling?

The term is a combination of 'prolactin,' a hormone named for its function in promoting lactation, and 'signaling,' referring to the process of transmitting information within or between cells. Prolactin was discovered in the early 20th century for its role in milk production. The 'signaling' component describes the subsequent molecular events that occur after the hormone binds to its cell surface receptor.

What is the Mechanism of Prolactin Signaling?

Prolactin signaling operates predominantly through the Janus kinase/Signal Transducers and Activators of Transcription (JAK/STAT) pathway. Upon prolactin binding to its receptor, the associated JAK kinases are activated, which then phosphorylate the receptor itself and STAT proteins. The phosphorylated STAT proteins dimerize and translocate to the cell nucleus, where they bind to specific DNA sequences to regulate the transcription of target genes, such as those involved in milk protein synthesis.

Prolactin Signaling ∞ Area

Prolactin Signaling

Meaning

The biochemical pathway initiated by the binding of the peptide hormone prolactin to its specific receptor on target cells, primarily within the mammary glands, but also in the brain, immune system, and reproductive organs. This signaling cascade is crucial for lactation, but it also plays roles in immune modulation, metabolism, and behavior. Dysregulation of prolactin signaling, often due to pituitary adenomas or certain medications, can lead to conditions like hyperprolactinemia, which impacts fertility and bone health.