β-Adrenergic stimulation of protein (arginine) methyltransferase acitivity in cultured cererbral cells from embryonic mice

✍ Scribed by Dr. S.G. Amur; G. Shanker; Dr. R.A. Pieringer

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 638 KB
• Volume: 16
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490160205

✦ Synopsis

Several adrenergic effectors and neurotransmitters were tested as potential regulators of myelin basic protein (MBP) and histone methyltransferase activities. Both enzymes were specifically activated by 0-adrenergic agonists in a stereospecific manner. Cyclic AMP (but not AMP) stimulated the enzymes to the same extent as did the P-adrenergic agonist, (-) isoproterenol. The studies suggest that /3adrenergic agonists stimulate adenylate cyclase thereby causing an increased production of cyclic AMP which stimulates the methyltransferases. Cycloheximide addition to the reaction mixture did not affect the stimulation due to cyclic AMP, indicating that new protein synthesis is not involved in the cyclic AMP stimulation of the methyltransferases. Thyroid hormone (T3) has been shown to stimulate MBP methyltransferase [Amur et al, 19841 and could exert its stimulatory effect through 6-adrenergic-dependent systems. But the /3-adrenergic antagonist, propranolol, did not block the stimulation by T3, suggesting that the effect of T3 is not mediated through P-adrenergic-dependent systems. Thus, the methylation of MBP seems to be regulated both by T3 and by neurotransmitters and/or hormones mediating their effects through cyclic AMP production, whereas the methylation of histones seems to be regulated only by the latter.