PREP1, MEIS1 homolog protein, regulates PF4 gene expression.
We have previously demonstrated that homeodomain proteins, MEIS1 and PBXs, transactivate the PF4 gene through the novel regulatory element termed TME. This study focuses on Pbx regulating protein 1 (PREP1), a MEIS1 homolog protein, for its transcriptional activity in the PF4 promoter. PREP1 binds to the TME in HEL cells. PREP1 was expressed in human megakaryocytes that differentiated from CD34(+) cells. EMSA shows that either PREP1 by itself or PREP1/PBX complexes bind to the two TGACAG motifs in the TME and activate the PF4 promoter. Furthermore, PREP1 and PREP1/PBX complexes synergistically activate the PF4 promoter with GATA-1 and ETS-1. These data demonstrate that PREP1 is also an important transcription factor that regulates PF4 gene expression such as MEIS1. Additionally, these data imply functional similarities and differences between PREP1 and MEIS1 in the regulation of PF4 gene expression.
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yoshiaki
Y
Okada
Eri
E
Matsuura
Ryohei
R
Nagai
Takahiro
T
Sato
Ayako
A
Watanabe
Ikuo
I
Morita
Takefumi
T
Doi
D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D020014:K562 Cells; D008533:Megakaryocytes / Q000378:metabolism*; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins / Q000737:chemistry / Q000502:physiology; D010978:Platelet Factor 4 / Q000096:biosynthesis / Q000235:genetics*; D020218:Response Elements; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation
D018398:Homeodomain Proteins; C000616391:MEIS1 protein, human; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins; C106682:PKNOX1 protein, human; D014157:Transcription Factors; D010978:Platelet Factor 4