ISSN:
1471-4159
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Medizin
Notizen:
Abstract: Proline-directed protein kinase (PDPK), a complex of p34cdc2 and p58cyclin A, phosphorylates bovine neurofilaments (NFs) in vitro. Incubation of intact filaments with PDPK led to strong labeling of the heavy (NF-H) and middle (NF-M) molecular weight NF proteins and weaker labeling of the low molecular weight protein (NF-L). All three proteins were phosphorylated in solution, with the best substrate being NF-H. Proteins that had been dephosphorylated by enzymatic treatment were better substrates than native proteins—as many as 6 mol of phosphate were incorporated per mole of NF-H. Partial proteolytic cleavage experiments combined with two-dimensional peptide mapping indicated that NF-H and NF-M were phosphorylated predominantly in the tail domains, with some phosphate also appearing in the heads. Soluble NF-L is phosphorylated on the head domain peptide L-3, whereas NF-L within intact filaments is phosphorylated only on the tail domain peptide L-1. Phosphorylation does not lead to filament disassembly. A possible role for PDPK in NF phosphorylation in vivo is discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1471-4159.1992.tb11351.x
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