Mutation of a Lysine Residue in a Homeodomain Generates Dominant Negative Thyroid Transcription Factor 1†

Biochemistry ◽  
2004 ◽  
Vol 43 (39) ◽  
pp. 12489-12497 ◽  
Author(s):  
Li Yang ◽  
Dong Yan ◽  
Molly Bruggeman ◽  
Hong Du ◽  
Cong Yan
2005 ◽  
Vol 19 (7) ◽  
pp. 1779-1791 ◽  
Author(s):  
Helmut Grasberger ◽  
Usanee Ringkananont ◽  
Paule LeFrancois ◽  
Marc Abramowicz ◽  
Gilbert Vassart ◽  
...  

Abstract Mutations in the paired domain transcription factor PAX8 are a rare cause of congenital hypothyroidism due to thyroid dysgenesis. We identified a novel and unique PAX8 mutation segregating in seven affected members of a three-generations family. The mutation replaces an invariant serine residue within helix 2 of the paired DNA-binding domain for phenylalanine. The mutant protein (PAX8-S48F) does not induce the thyroglobulin promoter in nonthyroid cells, but displays almost half of wild-type PAX8 activity in thyroid cells. PAX8-S48F shows no defect in expression, nuclear targeting, or DNA binding and retains the ability to synergize with thyroid transcription factor 1 (TTF-1, NKX2.1). However, we found that in nonthyroid cells, the acetylation-independent synergism with the general transcriptional adaptor p300 is completely abrogated, suggesting that PAX8-S48F may be unable to efficiently recruit p300. Reconstitution experiments in nonthyroid cells reveal that TTF-1 can partially rescue PAX8-S48F/p300 synergism and thus reproduce the situation in thyroid cells. These functional characteristics result in a dominant negative effect of PAX8-S48F on coexpressed wild-type PAX8 activity, which is not observed in paired domain mutations with DNA binding defect. Our results describe the first dominant negative missense mutation in a paired domain and provide evidence for a crucial role of the p300 coactivator in mediating the functional synergism between PAX8 and TTF-1 in thyroid-specific gene expression.


Endocrinology ◽  
1998 ◽  
Vol 139 (6) ◽  
pp. 3014-3017 ◽  
Author(s):  
Koichi Suzuki ◽  
Yoshihiko Kobayashi ◽  
Ryohei Katoh ◽  
Leonard D. Kohn ◽  
Akira Kawaoi

2011 ◽  
Vol 207 (11) ◽  
pp. 686-690 ◽  
Author(s):  
Matthias Dettmer ◽  
Tae Eun Kim ◽  
Chan Kwon Jung ◽  
Eun Sun Jung ◽  
Kyo Young Lee ◽  
...  

2007 ◽  
Vol 131 (4) ◽  
pp. 582-587
Author(s):  
David N. Butcher ◽  
Peter Goldstraw ◽  
George Ladas ◽  
Michael E. Dusmet ◽  
Mary N. Sheppard ◽  
...  

Abstract Context.—Intraoperative distinction between primary and metastatic carcinomas in the lung at frozen section remains problematic. Objective.—To assess the value and practicality of immunohistochemistry for thyroid transcription factor 1 at the time of intraoperative frozen section. Design.—Thirty-three patients presented with either a solitary pulmonary mass or 2 pulmonary masses and a history of carcinoma in a different organ. In addition to routine frozen section for assessment of tumor type, we looked for expression of thyroid transcription factor 1, using the EnVision system with abridged methodology. Results.—Ten cases were positive for thyroid transcription factor 1, which was confirmed on subsequent paraffin sections. Nine of these were confirmed as primary pulmonary adenocarcinomas, but 1 case proved to be a rare false-positive metastatic colonic carcinoma. Twenty-three cases were negative on frozen section and reported as favoring metastatic disease. In all cases, additional immunohistochemical data increased diagnostic confidence, but particularly in cases of positive primary pulmonary tumors and in cases with disease metastatic from sites other than the large bowel. The average time in addition to that of the basic frozen section was 24 minutes per test with a cost of £32 (US$57). Conclusions.—Frozen section immunohistochemistry for thyroid transcription factor 1 shows specificity and sensitivity similar to those seen for formalin-fixed tissues and is feasible within the time frame of a thoracotomy. Diagnostic confidence is increased, especially with positive primary pulmonary tumors. However, its practice should be properly planned within an operative procedure as liberal usage will likely have significant staff and cost implications.


In Vivo ◽  
2018 ◽  
Vol 32 (6) ◽  
pp. 1571-1579 ◽  
Author(s):  
ROLANDAS ZABLOCKIS ◽  
EDVARDAS ŽURAUSKAS ◽  
EDVARDAS DANILA ◽  
VYGANTAS GRUSLYS

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