The net rse RT 97 R following total NFH expressohad plateaued at p21 ndcated the phosphorylatoof NFH contnues to rse durng adulthood for 12 months.Smarly, scatc nerve, RT 97 R ncreased four fold from p7 to p180 and plateaued at 2ears of age.By contrast, durng the same perod, SM 33 R rose mnmally, establshng the NF phosphorylatostate markedly ncreased durng maturatoand agng.order to examne the bass for the contnued NFH phosphorylatoand rses RT 97 eptope levels durng bramaturatoand agng after the levelng off of NFH expresson, we carried out Westerblot analyses othe knases and phosphatases thathave beeshowto regulate RT 97 eptope levels.The amounts of catalytc subunts of PP2Ac mmunoreactvty declned 5 fold betweep12 and 2yr.PP1 mmunoreactvty declned 2.8 fold,even so, PP2B ranges were not sgnfcantly altered durng ths perod.To verfy no matter whether PP2A actvty declnes durng maturatoand agng, we montored ts actvty.These more helpful hints information exposed that PP2A actvty rses sgnfcantly from p3 to p12 but thedeclnes 38% by betweep21 and 2ears of age.
PP1 actvty, whch was fve fold less thathat of PP2A, dd not decrease sgnfcantly durng maturty read this article and agng.Smar patterns of phosphatase alteratons have been observed scatc nerves from these mce, exactly where the catalytc subunt expressoof PP2A declned three.5 fold betweep12 and 2yr.Smarly, catalytc subunt expressoof PP1 declned 7 fold betweep12 and 2yr.yet, the expressolevels from the PP2B subunt have been not sgnfcantly altered durng ths perod.Proteknase actvatodecreased durng bramaturaton.p35, the major actvator of cdk5, sgnfcantly decreased wth age, whe ts catalytc subunt, cdk5 decreased margnally.Smarly, durng the perod of NFHhyperphosphorylatoErk1, two ranges decreased 28% relatve to ther levels durng early postnatal development.The ranges of JNK1, 2 also declned five.6 fold from p21 to 2yr and a further three.seven fold from p3 to p21.Smar changes expressoof these knases were observed scatc nerve durng maturatoand agng.4.DscussoNF phosphorylatostate nvolves a complicated stability betweeactvtes of multple knases and phosphatases.
We prevously dentfed the molecular determnants of the RT 97 eptope, whch s the major repeated phosphorylatomotf

along the extended C termnal domans of NFH and NFM, and showed that t cabe created by multple proteknases, ncludng Erk1,2, JNK1,two, and cdk5.here wehave showthat PP2A and PP2B modulate turnover of phosphate groups with the RT 97 phosphoeptope and, consequently, the phosphorylatostate of NFH C termnal domans ntact neurons.Prevous vtro studeshave recommended a part of PP1, PP2A and PP2B the dephosphorylatoof NFs.More, thas beeshowthat PP2A removes phosphates oKSPXK motfs othe NF ta domaadded by cdk5, despite the fact that ths motf represents only 20% with the total KSPs.