| The Iodine Group | ||
|
Home | Orthoiodosupplementation | Body | Disease | Special | Overviews |
||
|
|
Porra
Characterization and semiquantitative analyses of pendrin expressed in normal and tumoral human thyroid tissues.Porra V, Bernier-Valentin F, Trouttet-Masson S, Berger-Dutrieux N, Peix JL, Perrin A, Selmi-Ruby S, Rousset B. J Clin Endocrinol Metab. 2002 Apr;87(4):1700-7.
"The gene mutated in
Pendred syndrome (PDS), the PDS gene, is expressed in the inner
ear, kidney, and thyroid. It encodes a membrane protein named
pendrin that is endowed with the function of anion transporter or
exchanger. It has been postulated that in the thyroid pendrin
could participate in the transport of iodide from the cell to the
lumen of follicles. We generated antipeptide antibodies directed
against the C- terminal sequence of human pendrin 1) to
characterize the protein expressed in the human thyroid, and 2)
to analyze its expression level in relation to the functional
activity of thyroid tissue. In denaturing conditions, a single
molecular species of 110-115 kDa was identified in human thyroid
membrane fractions. After treatment of thyroid membranes with
N-glycosidase F, pendrin had an apparent molecular mass of 85 kDa.
Analyzed by ultracentrifugation on sucrose gradient in
nondenaturing conditions, pendrin sedimented as a main 120- to
140-kDa component. Pendrin was assayed by semiquantitative
Western blot in thyroid membrane fractions from 25 hyper- or
hypofunctioning tumors and paired normal tissue samples. Pendrin
was increased 2-fold in toxic adenomas, was not significantly
altered in follicular adenoma, and was decreased, on the average,
by 35% in papillary carcinomas compared with levels in paired
normal tissue. The variations in the pendrin tissue content and
PDS transcript levels, assayed by RT-PCR on duplicate samples of
the same tumors, were similar. In conclusion, we show that
pendrin expressed by the human thyroid gland is a mainly
monomeric glycoprotein and that the level of expression of
pendrin, although somewhat related, only moderately varied with
the functional status of the thyroid tissue." |
|
Home | Orthoiodosupplementation | Body | Disease | Special Topics | OverviewsThe Iodine Group | Books | Disclaimers | Contact Us | SearchCopyright: Zoe, 2006. |
||