Cloning of a coproporphyrinogen oxidase promoter regulatory element binding protein.
Coproporphyrinogen oxidase [CPO] gene promoter regulatory element (CPRE) plays an important role in CPO gene regulation. To isolate a CPRE binding protein, we performed Southwestern screening of K562 cDNA expression library using CPRE as a probe and isolated a cDNA clone which encoded a novel protein, Klp1 (K562 cell-derived leucine-zipper-like protein 1). Klp1 mRNA was highly expressed in K562 cells, HeLa cells, and brain as a single transcript (1.4 kb). Gel mobility shift assays revealed that Klp1 specifically binds to CPRE. Computational analysis revealed that Klp1 has a leucine-zipper-like structure, a Leu-X-X-Leu-Leu motif, and a putative nuclear localization signal in the basic amino acid rich region. Transfection of the Klp1 expression vector into THP-1 cells resulted in transcriptional activation of a reporter construct containing CPRE. These results indicate that Klp1 is a DNA sequence-specific transcription factor that regulates gene expression of genes that contain CPRE in their regulatory region.
Takahashi
S
S
Department of Biochemistry, Tohoku University School of Medicine, Sendai, 980-8575, Japan.
Furuyama
K
K
Kobayashi
A
A
Taketani
S
S
Harigae
H
H
Yamamoto
M
M
Igarashi
K
K
Sasaki
T
T
Hayashi
N
N
D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D003304:Coproporphyrinogen Oxidase / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D020014:K562 Cells; D008969:Molecular Sequence Data; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D020298:U937 Cells
D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D003304:Coproporphyrinogen Oxidase