Novel repressor of the human FMR1 gene - identification of p56 human (GCC)(n)-binding protein as a Krüppel-like transcription factor ZF5.
A series of relatively short (GCC)(n) triplet repeats (n = 3-30) located within regulatory regions of many mammalian genes may be considered as putative cis-acting transcriptional elements (GCC-elements). Fragile X-mental retardation syndrome is caused by an expansion of (GCC)(n) triplet repeats within the 5'-untranslated region of the human fragile X-mental retardation 1 (FMR1) gene. The present study aimed to characterize a novel human (GCC)(n)-binding protein and investigate its possible role in the regulation of the FMR1 gene. A novel human (GCC)(n)-binding protein, p56, was isolated and identified as a Krüppel-like transcription factor, ZF5, by MALDI-TOF analysis. The capacity of ZF5 to specifically interact with (GCC)(n) triplet repeats was confirmed by the electrophoretic mobility shift assay with purified recombinant ZF5 protein. In cotransfection experiments, ZF5 overexpression repressed activity of the GCC-element containing mouse ribosomal protein L32 gene promoter. Moreover, RNA interference assay results showed that endogenous ZF5 acts as a repressor of the human FMR1 gene. Thus, these data identify a new class of ZF5 targets, a subset of genes containing GCC-elements in their regulatory regions, and raise the question of whether transcription factor ZF5 is implicated in the pathogenesis of fragile X syndrome.
Orlov
Sergey V
SV
Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St Petersburg, Russia. serge@iem.sp.ru
Kuteykin-Teplyakov
Konstantin B
KB
Ignatovich
Irina A
IA
Dizhe
Ella B
EB
Mirgorodskaya
Olga A
OA
Grishin
Alexander V
AV
Guzhova
Olga B
OB
Prokhortchouk
Egor B
EB
Guliy
Pavel V
PV
Perevozchikov
Andrej P
AP
D000595:Amino Acid Sequence; D001483:Base Sequence; D045744:Cell Line, Tumor; D015536:Down-Regulation; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D051860:Fragile X Messenger Ribonucleoprotein 1; D051741:Kruppel-Like Transcription Factors; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C497683:FMR1 protein, human; C489978:ZBTB14 protein, human