ZBP-89, a Krüppel-like zinc finger protein, inhibits epidermal growth factor induction of the gastrin promoter

JL Merchant, GR Iyer, BR Taylor… - … and cellular biology, 1996 - Am Soc Microbiol
JL Merchant, GR Iyer, BR Taylor, JR Kitchen, ER Mortensen, Z Wang, RJ Flintoft, JB Michel
Molecular and cellular biology, 1996Am Soc Microbiol
We have shown previously that a GC-rich element (GGGGCGGGGTGGGGGG) conferring
epidermal growth factor (EGF) responsiveness to the human gastrin promoter binds Sp1 and
additional undefined complexes. A rat GH 4 cell line expression library was screened by
using a multimer of the gastrin EGF response element, and three overlapping cDNA clones
were identified. The full-length rat cDNA encoded an 89-kDa zinc finger protein (ZBP-89)
that was 89% identical to a 49-kDa human factor, htβ, that binds a GTGGG/CACCC element …
Abstract
We have shown previously that a GC-rich element (GGGGCGGGGTGGGGGG) conferring epidermal growth factor (EGF) responsiveness to the human gastrin promoter binds Sp1 and additional undefined complexes. A rat GH 4 cell line expression library was screened by using a multimer of the gastrin EGF response element, and three overlapping cDNA clones were identified. The full-length rat cDNA encoded an 89-kDa zinc finger protein (ZBP-89) that was 89% identical to a 49-kDa human factor, htβ, that binds a GTGGG/CACCC element in T-cell receptor promoters. The conservation of amino acids between the zinc fingers indicates that ZBP-89 is a member of the C 2 H 2 zinc finger family subclass typified by the Drosophila Krüppel protein. ZBP-89 is ubiquitously expressed in normal adult tissues. It binds specifically to the gastrin EGF response element and inhibits EGF induction of the gastrin promoter. Collectively, these results demonstrate that ZBP-89 functions as a repressor of basal and inducible expression of the gastrin gene.
American Society for Microbiology