These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: ATP-induced stimulation of the intralysosomal hydrolysis of thyroglobulin. Evidence for an ATP-driven proton pump in thyroid lysosomes.
    Author: Fouchier F, Mego JL, Dang J, Simon C.
    Journal: Horm Metab Res; 1984 Jul; 16(7):359-62. PubMed ID: 6092251.
    Abstract:
    It is commonly admitted that the intralysosomal hydrolysis of thyroglobulin, which promotes thyroid hormonal secretion, requires an acidic pH. As a consequence the mechanisms by which such an acidic pH is set-up and maintained present an acute physiological interest. In the present work the extent of the intralysosomal hydrolysis of thyroglobulin (amount of TCA-soluble radioiodine formed during incubations of isolated thyroid lysosomes) has been retained as an index for the intralysosomal pH. Incubations in highly concentrated (250 mM) alkaline buffer, preincubations at 0 degree C in the presence of alkaline buffers or of methylamine, and incubations in the presence of FCCP (protonophore which dissipates proton-gradients) induced alkalinization of the lysosomal matrix (significant inhibition of thyroglobulin degradation). Addition of ATP to the incubation medium was shown to prevent these alkalinizations and to re-establish the acidic intralysosomal pH (normal thyroglobulin degradation) every time it had been experimentally increased. These results argue in favour of the existence of an ATP-driven proton pump in the membranes of thyroid lysosomes.
    [Abstract] [Full Text] [Related] [New Search]