PubMed Journals: J Neurochem
Source: PMID: 9453548
⇦ ⇨ J Neurochem. 1998 Feb;70(2):540-9.
Peripherin is tyrosine-phosphorylated at
its carboxyl-terminal tyrosine.
Angelastro JM(1), Ho CL, Frappier T, Liem
RK, Greene LA.
(1) Department of Pathology and Center for
Neurobiology and Behavior, College of Physicians
and Surgeons of Columbia University, New
York, New York 10032, USA.
Peripherin is a type III intermediate filament
present in peripheral and certain CNS neurons.
We report here that peripherin contains
a phosphotyrosine residue and, as such,
is the only identified intermediate filament
protein known to be modified in this manner.
Antiserum specific for phosphotyrosine recognizes
peripherin present in PC12 cells (with or
without nerve growth factor treatment)
and in rat sciatic nerve as well as that
expressed in Sf-9 cells and SW-13 cl. 2
vim- cells. The identity of peripherin as
a tyrosine-phosphorylated protein in PC12
cells was confirmed by immunoprecipitation,
two-dimensional isoelectric focusing/sodium
dodecyl sulfate-polyacrylamide gel electrophoresis
gels, and phosphoamino acid analysis. Unlike
serine/threonine phosphorylation, tyrosine
phosphorylation of peripherin is not regulated
by depolarization or nerve growth factor
treatment. To identify the site of tyrosine
phosphorylation, rat peripherin was mutated
at several tyrosine residues and expressed
in SW-13 cl. 2 vim- cells. Tyrosine phosphorylation
was selectively lost only for peripherin
mutants in which the carboxy-terminal tyrosine (Y474)
was mutated. Indirect immunofluorescence
staining indicated that both wild-type peripherin
and peripherin Y474F form a filamentous
network in SW-13 cl. 2 vim- cells. This
indicates that tyrosine phosphorylation
of the peripherin C-terminal residue is
not required for assembly and leaves open
the possibility that this modification serves
PMID: 9453548 [Indexed for MEDLINE]