Author(s)

Kanako Obayashi, Kayoko Takada, Kazuaki Ohashi, Ayako Kobayashi-Ohashi, Masatomo Maeda

Department of Immunobiology, School of Pharmacy, Iwate Medical University, Shiwa-Gun, Japan.
Department of Molecular Biology, School of Pharmacy, Iwate Medical University, Shiwa-Gun, Japan.
Departments of Medical Biochemistry, School of Pharmacy, Iwate Medical University, Shiwa-Gun, Japan.
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan.

GATA-6 mRNA utilizes two Met-codons in frame as translational initiation codons in cultured mammalian cells. Deletion of the nucleotide sequence encoding the PEST sequence between the two initiation codons unusually reduced the protein molecular size on SDS-polyacrylamide gel-electrophoresis. The reduced molecular size is ascribed to the molecular property of GATA-6, since both amino-and carboxy-lterminal tags introduced into GATA-6 were detected on the gel. This PEST sequence seems to contribute to expansion of the long-type GATA-6 molecule. The long-type GATA-6 containing the PEST sequence exhibits more activation potential than that without this sequence, the latter’s activity being similar to that of the short-type GATA-6. We further demonstrated that human colon and lung cancer cell lines express both the long-type GATA-6 and the short-type GATA-6 in their nuclei.

DNA-Binding Protein; GATA-6; Transcription Factor; Leaky Ribosome Scanning; PEST Sequence; Gel Electrophoresis

Obayashi, K. , Takada, K. , Ohashi, K. , Kobayashi-Ohashi, A. and Maeda, M. (2012) Role of the PEST sequence in the long-type GATA-6 DNA-binding protein expressed in human cancer cell lines. Advances in Bioscience and Biotechnology, 3, 314-320. doi: 10.4236/abb.2012.34045.