Molecular and functional characterization of the murine ldh2 promoter region: Sp-binding GC-box domains are the key cis-elements regulating ldh2 gene expression during spermatogenesis.
The goal of the present study was to elucidate the specific transcriptional mechanisms that regulate ldh2 gene expression during the early stages of spermatogenesis. DNA sequence analysis of the 1.0-kb ldh2 promoter region directly upstream of the transcriptional start site indicated the presence of three SP-protein binding GC-box elements and the absence of TATA and CAAT boxes. Functional characterization studies of the mouse ldh2 promoter were performed in the SV40 transformed mouse spermatogonial cell line, GC-1 spg. Transfection/transient expression studies using full-length and truncated ldh2 promoter/luciferase reporter constructs revealed that all three of the SP-binding cis-regulatory GC-box elements are required for optimal ldh2 promoter activity. Additional site-directed mutagenesis studies indicated that the two most proximal GC-box sites play essential regulatory roles in mediating basal ldh2 promoter activity. These studies suggest that the expression of the ldh2 gene in spermatogonia and early spermatocytes are regulated by SP-mediated transcriptional mechanisms.
Chen
Xing
X
Department of Anatomy and Neurobiology, Morehouse School of Medicine, Atlanta, GA 30310, United States.
Yang
Jun
J
Sung
Dae-Yong
DY
Thompson
Winston
W
Walker
William
W
Thomas
Kelwyn
K
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002461:Cell Line, Transformed; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D051705:Sp3 Transcription Factor / Q000378:metabolism*; D013091:Spermatogenesis / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D007527:Isoenzymes; D016329:Sp1 Transcription Factor; C497122:Sp3 protein, mouse; D051705:Sp3 Transcription Factor; D007770:L-Lactate Dehydrogenase; C409676:lactate dehydrogenase 2