Tissue-specific posttranslational modification allows functional targeting of thyrotropin.

ABSTRACT: Thyroid-stimulating hormone (TSH; thyrotropin) is a glycoprotein secreted from the pituitary gland. Pars distalis-derived TSH (PD-TSH) stimulates the thyroid gland to produce thyroid hormones (THs), whereas pars tuberalis-derived TSH (PT-TSH) acts on the hypothalamus to regulate seasonal physiology and behavior. However, it had not been clear how these two TSHs avoid functional crosstalk. Here, we show that this regulation is mediated by tissue-specific glycosylation. Although PT-TSH is released into the circulation, it does not stimulate the thyroid gland. PD-TSH is known to have sulfated biantennary N-glycans, and sulfated TSH is rapidly metabolized in the liver. In contrast, PT-TSH has sialylated multibranched N-glycans; in the circulation, it forms the macro-TSH complex with immunoglob

SUBMITTER: Ikegami K 

PROVIDER: S-EPMC4251493 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature