The actin cytoskeleton mediates the hormonally regulated translocation of type II iodothyronine 5'-deiodinase in astrocytes

UMMS Affiliation

Department of Nuclear Medicine; Department of Medicine, Division of Endocrinology & Metabolism; Department of Physiology

Publication Date


Document Type



Actins; Affinity Labels; Animals; Astrocytes; Biological Transport; Bucladesine; Cell Compartmentation; Cell Membrane; Cytoskeleton; Fluorescent Antibody Technique; Intracellular Membranes; Iodide Peroxidase; Membrane Proteins; Rats; Rats, Inbred Strains; Subcellular Fractions; Thyroxine


Life Sciences | Medicine and Health Sciences


Thyroid hormone, specifically thyroxine, alters cytoskeletal organization in astrocytes by modulating actin polymerization and, in turn, regulates the turnover of the short-lived membrane protein, type II iodothyronine 5'-deiodinase. In the absence of thyroxine, approximately 35% of the total cellular actin is depolymerized, and greater than 90% of the deiodinase is found in the plasma membrane and not associated with the cytoskeleton. Addition of thyroxine promotes actin polymerization and decreases the depolymerized actin to approximately 10% of the total actin pool, induces binding of the deiodinase to F-actin, and promotes rapid internalization of the enzyme. These data provide direct evidence that the actin cytoskeleton participates in the inactivation pathway of the deiodinase by translocating this short-lived plasma membrane protein to an internal membrane pool.


J Biol Chem. 1990 Oct 25;265(30):18546-53.

Journal/Book/Conference Title

The Journal of biological chemistry

Related Resources

Link to Article in PubMed

PubMed ID