ATF-7, a novel bZIP protein, interacts with the PRL-1 protein-tyrosine phosphatase.
We have identified a novel basic leucine zipper (bZIP) protein, designated ATF-7, that physically interacts with the PRL-1 protein-tyrosine phosphatase (PTPase). PRL-1 is a predominantly nuclear, farnesylated PTPase that has been linked to the control of cellular growth and differentiation. This interaction was initially found using the yeast two-hybrid system. ATF-7 is most closely related to members of the ATF/CREB family of bZIP proteins, with highest homology to ATF-4. ATF-7 homodimers can bind specifically to CRE elements. ATF-7 is expressed in a number of different tissues and is expressed in association with differentiation in the Caco-2 cell model of intestinal differentiation. We have confirmed the PRL-1.ATF-7 interaction and mapped the regions of ATF-7 and PRL-1 important for interaction to ATF-7's bZIP region and PRL-1's phosphatase domain. Finally, we have determined that PRL-1 is able to dephosphorylate ATF-7 in vitro. Further insight into ATF-7's precise cellular roles, transcriptional function, and downstream targets are likely be of importance in understanding the mechanisms underlying the complex processes of maintenance, differentiation, and turnover of epithelial tissues.
Peters
C S
CS
Department of Medicine, Division of Gastroenterology, University of Pennsylvania School of Medicine, Philadelphia 19104-6145, USA.
Liang
X
X
Li
S
S
Kannan
S
S
Peng
Y
Y
Taub
R
R
Diamond
R H
RH
D051696:Activating Transcription Factors; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D018938:Caco-2 Cells; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D019281:Dimerization; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D016350:Leucine Zippers; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017368:Protein Prenylation; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques; D014443:Tyrosine / Q000378:metabolism
C427752:ATF7 protein, human; D051696:Activating Transcription Factors; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D017874:Immediate-Early Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D014157:Transcription Factors; D014443:Tyrosine; D000242:Cyclic AMP; D005982:Glutathione Transferase; C490198:PTP4A1 protein, human; D017027:Protein Tyrosine Phosphatases; C087359:Ptp4a1 protein, mouse