Evidence for phosphorylation of CLN3 protein associated with Batten disease.
Recently, the CLN3 gene associated with Batten disease (juvenile neuronal ceroid lipofuscinosis, JNCL), a recessively inherited, progressive, neurodegenerative disorder of childhood, has been identified. The CLN3 gene encodes a novel protein (battenin) of a predicted 438 amino acids containing several potential posttranslational modifications. We have expressed a full-length CLN3 protein as a C-terminal fusion with green fluorescent protein (GFP) to evaluate whether CLN3 protein is phosphorylated. By using in vivo labeling with 32P, detection with anti-phosphoamino acid antibodies, and phosphoamino acid analysis, we demonstrate that the CLN3 protein is phosphorylated on both serine and threonine residues. We also demonstrate that CLN3 protein is not modified by mannose 6-phosphate. Furthermore, we show that phosphorylation of CLN3 protein is carried out by protein kinase A (cAMP-dependent protein kinase, PKA), protein kinase G (cGMP-dependent protein kinase, PKG), and casein kinase II and that it is enhanced by inhibition of protein phosphatase 1 (PP 1) or protein phosphatase 2A (PP 2A).
Michalewski
M P
MP
Department of Pathological Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island 10314, USA.
Kaczmarski
W
W
Golabek
A A
AA
Kida
E
E
Kaczmarski
A
A
Wisniewski
K E
KE
D000818:Animals; D016466:CHO Cells; D047390:Casein Kinase II; D006224:Cricetinae; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D018832:Molecular Chaperones; D009472:Neuronal Ceroid-Lipofuscinoses / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism
C105199:CLN3 protein, human; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D018832:Molecular Chaperones; D011506:Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D013912:Threonine; D012694:Serine; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D017869:Cyclic GMP-Dependent Protein Kinases