Research compendium
Prolactin
Prolactin is a protein hormone studied in cellular signaling and mammary-development and reproduction models. Nb2 cells have been used to examine its receptor’s connection with JAK2. Cellular findings and receptor-deletion animal models answer complementary but different questions.
This is a research reference, not a product offered in the Asciende catalog. Published studies do not establish the identity, purity or availability of a commercial preparation.
Input signal and axis response
Distinguish local mechanism from integrated effect. A whole-axis result needs its time context and cannot be summarized by a receptor name.
- Which level of the endocrine axis was manipulated and which was measured?
- Does the readout depend on pulses, time or system feedback?
- Are molecular forms or the preparation unambiguously described?
Mechanism described in the literature
In Nb2 cells in vitro, prolactin exposure was associated with JAK2 and receptor phosphorylation and cell proliferation. The study identified JAK2 as a receptor-associated kinase; it did not assign intrinsic kinase activity to the receptor or establish uniform responses across tissues.
Classification
Protein hormone
Other names
- PRL
- Prolactin
Early events and proliferation operate at different scales
The cell study separated early phosphorylation from later proliferation. Responses depended on concentration and did not increase without limit. A lower-signal point alone therefore establishes neither loss of material identity nor absence of interaction.
Reproductive history changed the mouse phenotype
Female mice heterozygous for PRLR deletion showed altered mammary development and lactation particularly after the first pregnancy, with different later behavior. The phenotype cannot be described uniformly while omitting genotype and reproductive history.
Receptor deletion differs from withdrawing a preparation
Female mice without functional PRLR had reproductive defects including absent embryo implantation. This intervention changes receptor availability throughout development. It is not a direct comparison of prolactin formulations or proof that every trait depends exclusively on acute hormone action.
Questions and answers
Are PRLR and JAK2 the same protein?
No. Nb2 work identified association between the receptor and a separate kinase.
Does the genetic model predict human response?
Not directly. It describes mouse PRLR-deletion consequences and must retain that limit.
Sources
- Prolactin-induced proliferation of Nb2 cells involves tyrosine phosphorylation of the prolactin receptor and its associated tyrosine kinase JAK2. — J Biol Chem (1994); PMID 8188682
- Null mutation of the prolactin receptor gene produces multiple reproductive defects in the mouse. — Genes Dev (1997); PMID 9009200; DOI 10.1101/gad.11.2.167
- Null mutation of the prolactin receptor gene produces multiple reproductive defects in the mouse. — Genes Dev (1997); PMID 9009200; DOI 10.1101/gad.11.2.167