Abnormal kappa B-binding protein in the cytoplasm of a plasmacytoma cell line that lacks nuclear expression of NF-kappa B.
The transcription factor NF-kappa B appears to play an important role in immunoglobulin gene expression and lymphokine production, and may play a role in primary B cell activation. Constitutive nuclear expression of NF-kappa B has been found in all mature B cell lines with the notable exception of the murine plasmacytoma, S107. We report herein that S107 cells express cytoplasmic kappa B-binding material detected by electrophoretic mobility shift assay that by several criteria represents authentic NF-kappa B. Despite the presence of cytoplasmic NF-kappa B, several stimuli known to induce nuclear translocation of NF-kappa B failed to do so in S107 cells, including: the PKC agonist, PMA; the protein synthesis inhibitor, cycloheximide; and LPS. Transfection of S107 cells with a kappa B-CAT reporter gene construct confirmed the absence of functional activity. Importantly, a global failure of nuclear transcription factor expression was ruled out by the ability of PMA to induce nuclear expression of another trans-acting factor, AP-1. Thus, rather than lacking NF-kappa B altogether, S107 cells manifest disordered regulation of NF-kappa B in which cytoplasmic material is incapable of translocation to the nucleus. While Northern analysis failed to reveal a gross defect in the mRNA coding for the DNA binding subunit of NF-kappa B, UV-photo-cross-linking followed by denaturing gel electrophoresis demonstrated the presence of a cytoplasmic kappa B-binding protein of abnormally elevated molecular size. This finding suggests that the abnormal regulation of NF-kappa B in S107 cells is associated with the appearance of an unusual kappa B-binding molecule.
Liu
J
J
Department of Microbiology, Boston University Medical Center, MA 02118.
Sen
R
R
Rothstein
T L
TL
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D004742:Enhancer Elements, Genetic / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects; D015759:Ionomycin; D051379:Mice; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects; D009687:Nuclear Proteins / Q000096:biosynthesis; D010954:Plasmacytoma / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D000071701:Regulatory Factor X Transcription Factors; D013755:Tetradecanoylphorbol Acetate; D015534:Trans-Activators / Q000096:biosynthesis; D014157:Transcription Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D009687:Nuclear Proteins; D012333:RNA, Messenger; D000071701:Regulatory Factor X Transcription Factors; D015534:Trans-Activators; D014157:Transcription Factors; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate