Regulation of tristetraprolin during differentiation of 3T3-L1 preadipocytes.
Tristetraprolin is a zinc-finger-containing RNA-binding protein. Tristetraprolin binds to AU-rich elements of target mRNAs such as proto-oncogenes, cytokines and growth factors, and then induces mRNA rapid degradation. It was observed as an immediate-early gene that was induced in response to several kinds of stimulus, such as insulin and other growth factors and stimulators of innate immunity such as lipopolysaccharides. We observed that tristetraprolin was briefly expressed during a 1-8 h period after induction of differentiation in 3T3-L1 preadipocytes. Detailed analysis showed that tristetraprolin mRNA expression was stimulated by fetal bovine serum and differentiation inducers, and was followed by rapid degradation. The 3'UTR of tristetraprolin mRNAs contain adenine- and uridine-rich elements. Biochemical analyses using RNA pull-down, RNA immunoprecipitation and gel shift experiments demonstrated that adenine- and uridine-rich element-binding proteins, HuR and tristetraprolin itself, were associated with tristetraprolin adenine- and uridine-rich elements. Functional characterization confirmed that tristetraprolin negatively regulated its own expression. Thus, our results indicated that the tight autoregulation of tristetraprolin expression correlated with its critical functional role in 3T3-L1 differentiation.
Lin
Nien-Yi
NY
Department and Graduate Institute of Veterinary Medicine, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan.
Lin
Chung-Tien
CT
Chen
Yu-Ling
YL
Chang
Ching-Jin
CJ
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D047468:Immunoprecipitation; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D020871:RNA Stability / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D051816:Tristetraprolin / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
D004268:DNA-Binding Proteins; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D051816:Tristetraprolin