Transcriptional activator invasion domain

An example of this class of peptide is the 86-amino acid truKi-activating transcriptional activator (TAT) of HIV-1 (74,75). Following incubation with cultured cells, TAT protein is internalized and subsequently transactivates viral promoters (75). The protein has multiple facets invasion, nuclear trophism, and DNA binding (76-81). An invasion domain of TAT has been identified within amino acids 37 to 72 with the critical basic region from amino acids (49 to 57), also known as the minimal transduction domain, which consists of the sequence -Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-. Any deletion in the sequence caused a reduction in translocating activity (82-84). Other prominent CPPs are reviewed in References 73 and 85. 

The t(2 3)(ql3 p25) translocation, found in a subset of thyroid follicular carcinomas, results in fusion of the DNA binding domains of the thyroid transcription factor PAX-8 to domains A-F of the peroxisome proliferation-activated receptor (PPAR) y 1 (Hg. 10.13). Studies using PCR and immunohistochemistry demonstrated that most follicular carcinomas positive for PPAR Y were widely invasive while tumors lacking the rearrangement were PPAR y negative. Papillary carcinomas and Hurthle cell tumors were negative. Other studies, however, have reported positivity both in follicular carcinomas and adenomas. 

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