Molecular cloning and analysis of a group of genes differentially expressed in cells which overexpress the Hoxa-1 homeobox gene.
The homeobox gene Hoxa-1 is transcriptionally regulated by retinoic acid (RA) and encodes a transcription factor which has been shown to play important roles in cell differentiation and embryogenesis. In order to clone and characterize target genes of Hoxa-1, we utilized differential hybridization screening and cDNA subtractive hybridization methods to identify genes which are differentially expressed in F9-10, a murine F9 teratocarcinoma stem cell line which expresses high levels of exogenous Hoxa-1, compared to F9 wild-type stem cells, which do not express endogenous Hoxa-1 mRNA in the absence of RA. Twenty-eight candidate genes were identified; these genes encode very diverse proteins, including signaling molecules such as BMP-4, the enzyme superoxide dismutase, the cell adhesion molecule cadherin-6, proteins involved in gene transcription such as HMG-1 and SAP18, homeodomain-containing proteins Gbx-2 and Evx-2, and cell cycle regulatory proteins such as the retinoblastoma binding protein-2. Clone 104 encodes a novel protein; the expression of the clone 104 mRNA is also regulated in a fashion very similar to that of the exogenous Hoxa-1 gene in another F9 cell line, called F9-tet-Hoxa1-8, in which the exogenous Hoxa-1 mRNA expression is tightly regulated by a Tet-off gene expression system. These data strongly suggest that clone 104 is a direct downstream target of the transcription factor Hoxa-1. The cDNA sequence of clone 104 is related to that of human ubiquitin carboxyl-terminal hydrolase T. Further characterization of these putative Hoxa-1 target genes will aid in delineating the functions of the Hoxa-1 protein in the differentiation processes which occur during embryogenesis.
Shen
J
J
Department of Pharmacology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York, 10021, USA.
Wu
H
H
Gudas
L J
LJ
D000818:Animals; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000235:genetics; D015820:Cadherins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods*; D056970:Co-Repressor Proteins; D015870:Gene Expression / Q000502:physiology; D005820:Genetic Testing / Q000379:methods; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins / Q000235:genetics; D006655:Histone Deacetylases; D018398:Homeodomain Proteins; D006801:Humans; D051379:Mice; D010750:Phosphoproteins / Q000235:genetics; D011506:Proteins; D012333:RNA, Messenger / Q000032:analysis; D016601:RNA-Binding Proteins; D018168:Receptors, Retinoic Acid / Q000235:genetics; D050717:Retinoblastoma-Like Protein p130; D013234:Stem Cells / Q000166:cytology; D013482:Superoxide Dismutase / Q000235:genetics; D018243:Teratocarcinoma; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic / Q000502:physiology; D014407:Tumor Cells, Cultured; D014452:Ubiquitins / Q000235:genetics
C525809:BMP4 protein, human; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D015820:Cadherins; D002352:Carrier Proteins; D056970:Co-Repressor Proteins; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins; D018398:Homeodomain Proteins; D010750:Phosphoproteins; D011506:Proteins; C493837:RBL2 protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C493838:Rbl2 protein, mouse; D018168:Receptors, Retinoic Acid; D050717:Retinoblastoma-Like Protein p130; C498650:SAP18 protein, human; C498651:Sap18 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; D014452:Ubiquitins; C088144:HoxA protein; D013482:Superoxide Dismutase; D006655:Histone Deacetylases; C087310:K cadherin