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A novel seven transmembrane receptor induced during the early steps of astrocyte differentiation identified by differential expression
Author(s) -
De Smet Charles,
Nishimori Hiroyuki,
Furnari Frank B.,
Bögler Oliver,
Huang H.J. Su,
Cavenee Webster K.
Publication year - 2002
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2002.00847.x
Subject(s) - biology , transmembrane protein , astrocyte , microbiology and biotechnology , cellular differentiation , oligodendrocyte , gene expression , receptor , gene , cell type , rna splicing , myelin , genetics , rna , cell , central nervous system , neuroscience
The rat glial progenitor cell line CG‐4 can be induced to differentiate into either oligodendrocytes or type‐2 astrocytes. In order to identify genes whose expression varies coincident with such phenotypic differentiation, we employed representational difference analysis (RDA) of mRNA. Here, we report 38 cDNAs induced in type‐2 astrocytes, oligodendrocytes, or both differentiated states. Among these were known transcription factors, membrane receptors, extracellular matrix proteins, secreted signaling modulators, chromatin regulators and myelin sheath components. In addition several novel genes were identified; among these was a gene induced during the very early stages of astrocyte differentiation that we have named Ieda (induced e arly in differentiating astrocytes). Several Ieda transcripts were detected by RT‐PCR, and appeared to be produced by alternative splicing and promoter usage. The protein deduced from the longest Ieda mRNA exhibited sequence features characteristic of G‐protein coupled receptors, including seven putative transmembrane domains, while the shorter Ieda transcripts encoded proteins that lacked several transmembrane segments. In the adult rat, Ieda transcripts were found exclusively in brain and testis. In the developing rat brain, Ieda expression was first detected at embryonic day 16, that is two days before the first appearance of mature astrocytes. Thus, this approach has yielded a potential source of markers for differentiation states of these two cellular types as well as genes predicted to be functionally involved in the differentiation process itself.