title: Transcriptional activity of erythroid Kruppel-like factor (EKLF/KLF1) modulated by PIAS3 (protein inhibitor of activated STAT3).
abstract: Erythroid Kruppel-like factor (EKLF or KLF1) is a transcription factor crucial for red cell development that is directly involved in regulation of a large number of erythroid genes. EKLF serves mostly as an activator of expression of these genes; however, it can act also as a repressor. Here, we present evidence that EKLF interacts with proteins from the PIAS (protein inhibitor of activated STAT) family that convey repressive activity to EKLF in the absence of sumoylation. Our studies identify PIAS3 as a transcriptional corepressor of EKLF for at least a subset of its target genes during erythropoiesis (e.g. β-globin, α-hemoglobin stabilizing protein). We demonstrate an interaction between EKLF and PIAS proteins confirmed by in vivo coimmunoprecipitation assays with both exogenous and endogenous proteins. We identified an LXXLL signature motif located near the N terminus of PIAS proteins that, although not involved in the EKLF-PIAS3 interaction, is required for the transrepression activity. Knockdown of endogenous PIAS3 accelerates differentiation of both murine erythroleukemia cells, as well as fetal liver cells, whereas an increase in PIAS3 levels inhibits this increase. Using chromatin immunoprecipitation assays, we show that PIAS3 preferentially occupies the β-globin promoter in undifferentiated murine erythroleukemia cells. Together these results demonstrate that an interaction between EKLF and PIAS3 provides a novel mode of regulation of EKLF activity in the absence of sumolylation and furthermore shows an important involvement of PIAS proteins in erythropoiesis.
authors.affiliation: From the Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029 and the Department of Genetics, Institute of Experimental Biology, University of Adam Mickiewicz, 61-614 Poznan, Poland msiatecka@amu.edu.pl.
authors.forename: Miroslawa
authors.initials: M
authors.lastname: Siatecka
authors.affiliation: From the Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029 and.
authors.forename: Shefali
authors.initials: S
authors.lastname: Soni
authors.affiliation: From the Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029 and.
authors.forename: Antanas
authors.initials: A
authors.lastname: Planutis
authors.affiliation: From the Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029 and.
authors.forename: James J
authors.initials: JJ
authors.lastname: Bieker
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D019556:COS Cells; D002454:Cell Differentiation / Q000235:genetics; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D057809:HEK293 Cells; D006801:Humans; D020014:K562 Cells; D051741:Kruppel-Like Transcription Factors / Q000235:genetics* / Q000378:metabolism; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051379:Mice; D018613:Microscopy, Confocal; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D050828:Protein Inhibitors of Activated STAT / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D058207:Sumoylation; D015533:Transcriptional Activation; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism
chemical_list: D051741:Kruppel-Like Transcription Factors; D050828:Protein Inhibitors of Activated STAT; D055544:beta-Globins; C080774:erythroid Kruppel-like factor
keywords: Cell Differentiation; Erythropoiesis; Gene Regulation; Kruppel-like Factor (KLF); LXXLL Motif; PIAS3; SAP Domain; Transcription Coregulator