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Active polysomes in the axoplasm of the squid giant axon
Author(s) -
Giuditta Antonio,
Menichini E.,
Capano C. Perrone,
Langella M.,
Martin R.,
Castigli E.,
Kaplan B. B.
Publication year - 1991
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490280103
Subject(s) - axoplasm , squid giant axon , axon , polysome , neurofilament , squid , biology , axoplasmic transport , microbiology and biotechnology , neuroscience , biophysics , biochemistry , rna , ribosome , gene , ecology , immunohistochemistry , immunology
Axons and axon terminals are widely believed to lack the capacity to synthesize proteins, relying instead on the delivery of proteins made in the perikaryon. In agreement with this view, axoplasmic proteins synthesized by the isolated giant axon of the squid are believed to derive entirely from periaxonal glial cells. However, squid axoplusm is known to contain the requisite components of an extra‐mitocliondrial protein synthetic system, including protdn factors, tRNAs, rRNAs, and a heterogeneous family of mRNAs. Hence, the giant axon could, in principle, maintain an endogenous protein synthetic capacity. Here, we report that the squid giant axon also contains active polysomes and niRNA, which hybridizes to a riboprobe encoding murine neurofilament protein. Taken together, these findings provide direct evidence that proteins (including the putative neuron‐specific neurofilament protein) are also synthesized de novo in the axonal compartment.