Identification of trophoblast-specific binding sites for GATA-2 that are essential for rat placental lactogen-I gene expression.
We identified a 3.4-kb 5'-flanking region of the rPL-I gene and examined its promoter activity using rat trophoblast Rcho-1 cells. A regulatory element between base pairs (bp) -2,487 and -2,310 in the 5'-flanking region was essential for maximum promoter activity of the rPL-I gene. This regulatory element was further characterized between bp -2,443 to -2,415 and -2,374 to -2,345. Electrophoretic mobility shift analysis showed that the interaction of nuclear extract proteins from differentiated Rcho-1 cells was inhibited by competition with a GATA-like sequence in the promoter, but not by a mutated GATA sequence. Moreover, the promoter activity of 2487 eLuc containing two novel GATA sites was significantly elevated by co-transfection of a GATA-2 expression vector in proliferating Rcho-1 cells. Our results demonstrate that GATA-2 is involved in multiple promoter regions to activate the specific expression of the rPL-I gene in placental tissue.
Kim
Gon-Sup
GS
Department of Anatomy, Institute of Life Science, College of Veterinary Medicine, Gyongsang National University, Jinju, Korea.
Ko
Yeoung-Gyu
YG
Park
Oh-Sung
OS
Park
Hyoung Joon
HJ
Koh
Phil-Ok
PO
Cho
Kyu-Woan
KW
Min
Kwan-Sik
KS
Seong
Hwan-Hoo
HH
Won
Chung-Kil
CK
Cho
Jae-Hyeon
JH
D024506:5' Flanking Region; D000818:Animals; D019677:Artificial Gene Fusion; D001665:Binding Sites; D024202:Electrophoretic Mobility Shift Assay; D050989:GATA2 Transcription Factor / Q000378:metabolism*; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D010928:Placental Lactogen / Q000096:biosynthesis*; D011485:Protein Binding; D051381:Rats; D050436:Regulatory Elements, Transcriptional; D014327:Trophoblasts / Q000502:physiology*
D050989:GATA2 Transcription Factor; C085699:placental lactogen I, rat; D010928:Placental Lactogen; D008156:Luciferases