Amino-terminal extension of 146 residues of L-type GATA-6 is required for transcriptional activation but not for self-association

作者：Takada Kayoko; Obayashi Kanako; Ohashi Kazuaki; Ohashi Kobayashi Ayako; Nakanishi Matsui Mayumi; Maeda Masatomo^*

来源：Biochemical and Biophysical Research Communications, 2014, 452(4): 962-966.

DOI：10.1016/j.bbrc.2014.09.019

• GATA-6
• Leaky ribosomal scanning
• PEST sequence
• Self-association
• Transcription factor

Transcription factor GATA-6 plays essential roles in developmental processes and tissue specific functions through regulation of gene expression. GATA-6 mRNA utilizes two Met-codons in frame as translational initiation codons. Deletion of the nucleotide sequence encoding the PEST sequence (Glu(31)-Cys(46)) between the two initiation codons unusually reduced the protein molecular size on SDS-polyacrylamide gel-electrophoresis, and re-introduction of this sequence reversed this change. The long-type CL-type) GATA-6 containing this PEST sequence self-associated similarly to the short-type (S-type) GATA-6, as determined on co-immunoprecipitation of Myc-tagged GATA-6 with HA-tagged GATA-6. The L-type and S-type GATA-6 also interacted mutually. The L-type GATA-6 without the PEST sequence also self-associated and interacted with the S-type GATA-6. The transcriptional activation potential of L-type GATA-6 is higher than that of S-type GATA-6. When the PEST sequence (Glu(31)-Cys(46)) was inserted into the L-type GATA-6 without Arg(13)-Gly(101), the resultant recombinant protein showed significantly higher transcriptional activity, while the construct with an unrelated sequence exhibited lower activity. These results suggest that the Glu(31)-Cys(46) segment plays an important role in the transcriptional activation, although it does not participate in the self-association.

• 出版日期2014-10-3