The protein product of the neurofibromatosis type 1 gene is expressed at highest abundance in neurons, Schwann cells, and oligodendrocytes

Neurofibromin, a predominantly neuronal GTPase activating protein in the adult, is ubiquitously expressed during development

“…1A). As we found in our previous study (Daston et al, 1992) these antibodies recognized a single band at 220 kDa. Under conditions of antibody excess, neurofibromin levels in the ventral portion, which included developing organs of the thoracic and abdominal cavities, was not different from the amount in the head and dorsal portion, which contained the brain and spinal cord respectively.…”

“…Under conditions of antibody excess, neurofibromin levels in the ventral portion, which included developing organs of the thoracic and abdominal cavities, was not different from the amount in the head and dorsal portion, which contained the brain and spinal cord respectively. Unlike the pattern seen in the adult (Daston et al, 1992), there was no preferential localization to the nervous system. Sagittal cryostat sections of whole E l 0 (Fig.…”

“…In a previous study, we analyzed the localization of neurofibromin in adult rats and humans (Daston et al, 1992; see also Hattori et al, 1991). The cellular distribution of neurofibromin was identical in the rat and human spinal cord, indicating that the rat is an appropriate model for human neurofibromin expression.…”

“…Neurofibromin is a 220-250 kDa protein DeClue et al, 1991;Hattori et al, 1991;Daston et al, 1992). Cloning and sequencing of the NF1 gene (Wallace et al, 1990;Viskochil et al, 1990;Cawthon et al, 1990;Buchberg et al, 1990;Xu et al, 1990b;Marchuk et al, 1991) revealed sequence homology to GTPase activating proteins (GAPS).…”

Haploinsufficiency for the neurofibromatosis 1 (NF1) tumor suppressor results in increased astrocyte proliferation

“…The NF1 tumor suppressor gene was identi®ed by positional cloning and found to encode a 220 ± 250 kiloDalton cytoplasmic protein termed neuro®bromin Viskochil et al, 1990;Wallace et al, 1990). Neuro®bromin is expressed in many cell types and tissues, including neurons, astrocytes, Schwann cells, oligodendrocytes, blood vessels, adrenal medulla, gonadal tissues, and white blood cells (DeClue et al, 1991;Gutmann et al, 1991Gutmann et al, , 1995Daston et al, 1992;Golubic et al, 1992;Datson and Ratner, 1993;Huynh et al, 1992). Sequence analysis demonstrated that a small central domain of neuro®bromin shares similarity with the catalytic domain of proteins involved in p21-ras regulation (Ballester et al, 1990;Martin et al, 1990;Xu et al, 1990a,b).…”