TY - JOUR
T1 - Differentiation-Dependent Activation of the Extracellular Fatty Acid Binding Protein (Ex-FABP) Gene during Chondrogenesis
AU - Giannoni, Paolo
AU - Zambotti, Adriana
AU - Pagano, Aldo
AU - Cancedda, Ranieri
AU - Dozin, Beatrice
PY - 2004/1
Y1 - 2004/1
N2 - Chicken hypertrophic chondrocytes secrete the extracellular fatty acid binding protein (Ex-FABP), a lipocalin not expressed by their undifferentiated precursors. Genomic clones coding for the full protein are here structurally and functionally analyzed. We first determined that the promoter sequence markedly differs from that reported for the homologous p20K, and we confirmed by genomic DNA Southern analysis the exactness of our sequence. This is of relevance since we have identified another lipocalin gene within the region of discrepancy, indicating thereby the existence of a lipocalin cluster within the same chromosomal locus. By transient transfections with 5′-deletions and the chloramphenicol acetyl transferase (CAT) reporter gene, the region between nt -926 and nt -629 was shown to be strongly active, specifically in hypertrophic chondrocytes and not in dedifferentiated cells. Responsive elements for several potential transcription factors lay within this sequence. Among those, activating protein-1 (AP-1) was shown to be involved in the regulation of the Ex-FABPgene during chondrocyte differentiation, as indicated by electrophoretic mobility shift assay, AP-1 site mutagenesis and functional interference assays.
AB - Chicken hypertrophic chondrocytes secrete the extracellular fatty acid binding protein (Ex-FABP), a lipocalin not expressed by their undifferentiated precursors. Genomic clones coding for the full protein are here structurally and functionally analyzed. We first determined that the promoter sequence markedly differs from that reported for the homologous p20K, and we confirmed by genomic DNA Southern analysis the exactness of our sequence. This is of relevance since we have identified another lipocalin gene within the region of discrepancy, indicating thereby the existence of a lipocalin cluster within the same chromosomal locus. By transient transfections with 5′-deletions and the chloramphenicol acetyl transferase (CAT) reporter gene, the region between nt -926 and nt -629 was shown to be strongly active, specifically in hypertrophic chondrocytes and not in dedifferentiated cells. Responsive elements for several potential transcription factors lay within this sequence. Among those, activating protein-1 (AP-1) was shown to be involved in the regulation of the Ex-FABPgene during chondrocyte differentiation, as indicated by electrophoretic mobility shift assay, AP-1 site mutagenesis and functional interference assays.
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U2 - 10.1002/jcp.10405
DO - 10.1002/jcp.10405
M3 - Article
C2 - 14584054
AN - SCOPUS:1642474380
VL - 198
SP - 144
EP - 154
JO - Journal of cellular and comparative physiology
JF - Journal of cellular and comparative physiology
SN - 0021-9541
IS - 1
ER -