Synthesis of a high molecular weight thyroglobulin dimer by two ovine thyroid cell lines: the OVNIS.
The OVNIS 6H and 5H thyroid cells, 2 permanent cell lines isolated 3 years ago from ovine tissue, synthesize a high molecular weight glycosylated protein, immunologically related to ovine thyroglobulin, which is similar to the prothyroid hormone dimer (17-19) S: thyroglobulin. Using sucrose gradient centrifugation and cell labelling with [14C]Leu or [3H]GlNH2, radioactivity was observed in proteins purified from cell layers and from cell culture media. Addition of thyrotropin to or removal from the media resulted respectively in an increase (+773%) or decrease (-1090%) of the total radioactivity detected in the (17-19)S thyroglobulin fraction. Estimation of thyroglobulin by RIA gave similar though less pronounced effects. These experiments prove (1) that thyroglobulin is still expressed in these OVNIS thyroid cell lines even after 3 years of permanent culture, (2) that TSH modulates the level of this protein through a TSH-receptor functional system.
S
S
Hovsépian
A
A
Aouani
G
G
Fayet
D000818:Animals; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D005944:Glucosamine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D046911:Macromolecular Substances; D008970:Molecular Weight; D012756:Sheep; D013954:Thyroglobulin / Q000096:biosynthesis*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology
D046911:Macromolecular Substances; D013972:Thyrotropin; D013954:Thyroglobulin; D007930:Leucine; D005944:Glucosamine