Subcellular localization of iodinated thyroid tubulin. Issue 3 (June 1989)

• Record Type: Journal Article
• Authors: Hargreaves, Alan J.; Lamas, Luis; Santisteban, Pilar; Avila, Jesus
• Is Part Of: Bioscience reports. Volume 9:Issue 3(1989)
• Page Start: 375
• Page End: 382
• Publication Date: 1989-06
• Subjects: thyroid membranes -- iodinated tubulin -- formic acid hydrolysis; Molecular biology -- Periodicals; Cytology -- Periodicals; 572.8
• DOI: 10.1007/BF01114691
• Languages: English
• ISSNs: 0144-8463

Abstract

Abstract : Subcellular fractions enriched in mitochondria, plasma membranes, microsomes and Golgi apparatus were obtained from thyroid glands of rats injected with I 125 . Autoradiography of SDS-polyacrylamide gels revealed the presence of a number of radiolabelled proteins in each membrane fraction. One polypeptide, with the same electrophoretic mobility as brain tubulin, was found in all fractions except the plasma membranes and was immunoprecipitated with commercial anti-tubulin monoclonal antibodies. Hydrolysis of Asp-Pro linkages of I 125 labelled tubulin with formic acid indicated that there were iodination sites in both the carboxy terminal one third and the amino terminal two thirds of the molecule. These results, together with the absence of iodinated tubulin from the cytosolic fraction, are consistent with the idea that a population of thyroid membrane tubulin is iodinated at multiple sites either just before or after insertion into intracellular membranes where it may act as an anchorage point for microtubule-membrane interactions.