Immediate-early response 5 (IER5) interacts with protein phosphatase 2A and regulates the phosphorylation of ribosomal protein S6 kinase and heat shock factor 1.
Immediate-early response 5 (IER5) is a growth factor-inducible protein with homology to the N-terminus of IER2. Deletion analysis shows that a large region of IER5, including the N-terminal region, is involved in cell growth and stress resistance. The N-terminal region mediates IER5 oligomerization and binding to the B55 regulatory subunit of protein phosphatase 2A (PP2A). IER5 physically interacts with the PP2A target proteins ribosomal protein S6 kinase (S6K) and heat shock factor 1 (HSF1), and the interactions are essential for the reduced phosphorylation of S6K and HSF1. Our data indicate that oligomeric IER5 regulates PP2A activity and cell growth.
Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
Shotaro
S
Kawabata
Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
Yuichiro
Y
Ishita
Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
Yukio
Y
Ishikawa
Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan. Electronic address: hsakurai@staff.kanazawa-u.ac.jp.
Hiroshi
H
Sakurai
D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D006801:Humans; D017874:Immediate-Early Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D055503:Protein Multimerization; D054648:Protein Phosphatase 2 / Q000737:chemistry / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000378:metabolism; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; D017874:Immediate-Early Proteins; D021122:Protein Subunits; D014157:Transcription Factors; D019893:Ribosomal Protein S6 Kinases; D054648:Protein Phosphatase 2
Heat shock factor 1; Immediate-early response 5; Phosphorylation; Protein phosphatase 2A; S6 kinase