EKLF/KLF1 is ubiquitinated in vivo and its stability is regulated by activation domain sequences through the 26S proteasome.
Erythroid Krüppel-like factor (EKLF/KLF1) is an erythroid specific, C(2)H(2) zinc finger transcription factor that is essential for the proper chromatin structure and expression of the adult beta-globin gene. Herein, we determine that 26S proteasome inhibitors lead to an accumulation of EKLF protein in murine erythroleukemia (MEL) cells. In addition, EKLF half-life in both MEL cells (<3h) and fetal liver cells (between 6 and 9h) is stabilized in the presence of these inhibitors. EKLF is ubiquitinated in vivo, however its modification does not rely on a particular internal lysine. Finally, EKLF contains two PEST sequences within its N-terminus that have no effect on the ability of EKLF to be ubiquitinated but contribute to its destabilization.
The Brookdale Department of Molecular, Cell and Developmental Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.
Karen J
KJ
Quadrini
James J
JJ
Bieker
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D002843:Chromatin / Q000378:metabolism; D005333:Fetus / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005914:Globins / Q000096:biosynthesis; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D051379:Mice; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism*
D002843:Chromatin; D051741:Kruppel-Like Transcription Factors; D025801:Ubiquitin; C080774:erythroid Kruppel-like factor; D005914:Globins; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D008239:Lysine