In Schwann cells, the transmembraen glycoprotein beta -dystroglycan compose
s the dystroglycan complex together with the extracellular glycoprotein alp
ha -dystroglycan, which binds laminin-2 (alpha2/beta1/gamma1), a major comp
onent of the Schwann cell basal lamina. In the Schwann cell cytoplasm, beta
-dystroglycan is anchored to a dystrophin isoform, Dp116. In this study, w
e investigated the expression of beta -dystroglycan, Dp116 and the laminin-
alpha2 chain in satellite cells of rat dorsal root ganglia (DRGs). Immunohi
stochemical study showed that immunoreactivities for beta -dystroglycan and
Dp116 were both localized to the outer rim of neuron-satellite cell and ax
on-Schwann cell units, indicating that both satellite and Schwann cells exp
ressed these proteins in DRGs. Immunoreactivity for the laminin-alpha2 chai
n was detected in a similar location, indicating that the basal lamina surr
ounding satellite and Schwann cells in DRGs contained laminin-2. Ultrastruc
turally, immunoreactivity for the cytoplasmic domain of beta -dystroglycan
as well as that for Dp116 was most intense in the cytoplasm just underlying
the outer membrane of satellite cells. The immunoreactivity for laminin wa
s associated with the outer surface of those cells, suggesting that it was
localized in the surrounding basal lamina. These results indicate that the
dystroglycan complex is expressed in the satellite cell outer membrane and
involved in the adhesion with the basal lamina through the interaction with
laminin-2.