Induction and quantitation of the RI cAMP-binding protein in clonal mouse neuroblastoma cell lines: evidence that the increase in RI is not linked to neurite outgrowth.
This is a study of the regulation of expression of the RI cAMP-binding protein in mouse neuroblastoma cells as it relates to neurotransmitter phenotype and neurite outgrowth. Dibutyryl cAMP was used to promote differentiation of the cholinergic NS-20, the adrenergic N1E-115, the neurotransmitter-inactive N-18, and the neurite-minus N1A-103 mouse neuroblastoma cells. The amount of the RI cAMP-binding protein was quantitated by photoaffinity labeling of the 47,000-dalton RI protein with 8-N3-[32P]cAMP and by Western blot, ELISA, and immunocytochemistry. Our results showed that dibutyryl cAMP induced the RI cAMP-binding protein by three to fivefold in each of the four neuroblastoma cell lines examined. The increased expression of the RI cAMP-binding protein was not linked to neurite outgrowth, a parameter of morphological differentiation in the neuroblastoma cells. Thus, the RI cAMP-binding protein can be induced in the neurite-minus N1A-103 neuroblastoma round cells; further, 8-bromo-cAMP effected neurite outgrowth without inducing the RI cAMP-binding protein in the neurite-positive cell lines. Indirect immunocytochemistry of RI showed a cytoplasmic localization with little evidence of nuclear staining. The increase in RI cAMP-binding protein coincided with an increase in the cAMP-phosphodiesterase and a decrease in cAMP-dependent phosphotransferase activity in the mouse neuroblastoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Liu
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AY
Department of Biological Sciences, Rutgers--State University of New Jersey, Piscataway 08855.
Lin
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Z
Kamalakannan
V
V
Chen
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KY
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000502:physiology; D003994:Bucladesine / Q000494:pharmacology; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000378:metabolism; D002460:Cell Line; D002999:Clone Cells; D002373:Cyclic AMP Receptor Protein; D003600:Cytosol / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D009447:Neuroblastoma; D006656:Protamine Kinase / Q000378:metabolism
D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D009363:Neoplasm Proteins; D003994:Bucladesine; D006656:Protamine Kinase; D015105:3',5'-Cyclic-AMP Phosphodiesterases