Immunoelectronmicroscopical localization of the three neurofilament triplet proteins along neurofilaments of cultured dorsal root ganglion neurones

Phosphorylation of neurofilament proteins and chromatolysis following transection of rat sciatic nerve

“…Perikaryal staining occurred preferentially in the large cell population, as noted by Anderton et al (1982), Sharp et al (1982), Lawson et al (1984), and Price (1985). The extent of immunoreactivity in neuronal perikarya, compared to that in axons, depended upon the specificity and titer of the antibody.…”

“…indicative of increased phosphorylation correlate closely with chromatolytic changes in DRG neurons, especially in neurons of large size, which preferentially express neurofilament proteins (Anderton et al, 1982;Sharp et al, 1982;Lawson et al, 1984;Price, 1985). The absence of neurofilament expression, or low levels thereof, would preclude the immunological detection of DRG neurons, as occurs with chromatolytic neurons of small size.…”

Expression of NF-L in both neuronal and nonneuronal cells of transgenic mice: increased neurofilament density in axons without affecting caliber.

“…Indeed, although NF-L can form filaments in the absence of the other subunits (Geisler and Weber, 1981;Liem and Hutchinson, 1982), it does not carry the extended carboxyterminal tail shared by NF-M and NF-H (Sharp et al, 1982;Hirokawa et al, 1984;Hisanaga and Hirokawa, 1988), which in the case of NF-H appears to be associated NF cross-bridges (Hirokawa et al, 1984;Hisanaga and Hirokawa, 1988). It is possible that these cross-bridges play a critical role in the regulation of axonal caliber.…”

Dynamics of neuronal intermediate filaments: A developmental perspective

“…A different type of neurofilament dynamics is governed in part by the phosphorylation state of the long, highly charged C-terminal tail regions of NF-M and NF-H, which are peripherally situated on the filament and may correspond to the sidearms of neurofilaments [Pant et al, 1978;Sharp et al, 1982;Leterrier et al, 1982;Hirokawa et al, 19841. The phosphorylation of many sites on the tail domains, which is mediated by one or more neuron-specific cytoskeletonassociated kinases Runge et al, 1981;Shecket and Lasek, 19821, is delayed until after neurofilaments have entered the axon and continues as neurofilaments are transported [Glicksman et al, 1987;Oblinger, 1987;Nixon et al, 19871.…”

“…The observation that the most extensively phosphorylated form of each subunit is associated with stationary neurofilaments [Lewis and Nixon, 19881 provided initial support for the idea that C-terminal tail phosphorylation regulates the relative affinity of neurofilament proteins for the transport mechanisms and for stationary struc-tures in the axon and therefore is one of the factors that controls the transport rate of neurofilament proteins Watson et al, 19911. This process may be facilitated by extension of the C-terminal domains radially from the neurofilament core Sharp et al, 1982;Leterrier et al, 1982;Hirokawa et al, 1984;Carden et al, 19871 or rigidification of this extended conformation by the addition of numerous charged groups to this region [Sternberger and Sternberger, 1983;Hagestedt et al, 19891. This process would be expected to hinder neurofilament movement sterically , possibly to reduce attachment to the transport vector, and to increase accessibility to new binding sites for cross-linking proteins all along the filament [Nixon and Sihag, 19911.…”