A possible role for the high mobility group box transcription factor Tcf-4 in vertebrate gut epithelial cell differentiation.
The Wingless (Wg)/Wnt signaling pathway activates High Mobility Group (HMG)-box transcription factors of the T-cell Factor (Tcf)/Lymphoid Enhancer Factor (LEF) subfamily and mediates diverse functions in development, possibly including endoderm and gut differentiation. Determinants of tissue specificity in the response to Wg/Wnt signaling remain unknown. We have identified Tcf-4 as the predominant Tcf/LEF factor in the developing mouse gut. During fetal development, Tcf-4 mRNA expression is restricted to gut epithelium and specific regions of the brain, the thalamus and roof of the midbrain. In adults, expression is widespread, with highest levels observed in the liver, an endodermally derived organ, and persists in the gastrointestinal tract. Murine Tcf-4 has multiple RNA splice variants with consequently significant heterogeneity in sequences 3' to the HMG box. Microinjection of mRNA or plasmid DNA encoding Tcf-4 into Xenopus embryos results in ectopic expression of molecular markers of endoderm and differentiated gut epithelium in isolated animal cap explants. Taken together, these findings point to a potentially important function for Tcf-4 in development of the vertebrate gastrointestinal tract.
Lee
Y J
YJ
Department of Adult Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Swencki
B
B
Shoichet
S
S
Shivdasani
R A
RA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D004064:Digestive System / Q000166:cytology / Q000196:embryology*; D005314:Embryonic and Fetal Development; D004847:Epithelial Cells / Q000166:cytology*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D051820:TCF Transcription Factors; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors / Q000378:metabolism*; D014981:Xenopus; D029867:Xenopus Proteins
D006609:High Mobility Group Proteins; D012333:RNA, Messenger; D051820:TCF Transcription Factors; C544894:TCF7L2 protein, human; C544895:Tcf7l2 protein, mouse; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors; D029867:Xenopus Proteins; C544896:tcf7l2 protein, Xenopus