Evidence for the presence of a type-III nitric oxide synthase-like protein
(NOS-III-like protein) in astroglial cells is reported, The mRNA of a NOS-I
II-like protein is constitutively expressed in human astrocytoma T67 cells,
taken as an astroglial model. The nucleotide sequence of the PCR product (
422 hp) shares more than 99% identity with the cDNA (from 1588 to 2009) of
the human endothelial nitric oxide synthase (NOS-III). The molecular mass o
f the astroglial NOS-III-like protein is about 140 kDa, as observed for hum
an NOS-III. Moreover, the astroglial NOS-III-like protein is constitutively
tyrosine-phosphorylated and associated with caveolin-1. The astroglial NOS
-III-like protein is apparently inactive, as reported for phosphorylated hu
man NOS-III associated with caveolin-1. (C) 1998 Academic Press.