Expression of glia maturation factor beta mRNA and protein in rat organs and cells.
Rat glia maturation factor beta (GMF-beta) cDNA was obtained by reverse transcription of rat brain mRNA followed by polymerase chain reaction amplification, using primers from the human sequence. The deduced amino acid sequence of rat GMF-beta differed from the human counterpart in only three places: His27 in place of Asn, Val51 in place of Ile, and Leu93 in place of Val. The high degree of evolutionary conservation suggests that GMF-beta plays an essential role in animal cell physiology. The expression of GMF-beta mRNA in the rat was studied by the northern blot technique, using a rat cRNA probe corresponding to the entire coding region. GMF-beta mRNA was predominantly expressed in the brain and spinal cord, although trace levels were found in other organs, including testis and ovary. In the brain GMF-beta mRNA was detectable at as early as embryonic day 10, and persisted through as late as postnatal month 14, with minor variations in between. On the other hand, GMF-beta protein exhibited more obvious developmental changes, with its level increasing slowly prenatally and plateauing at 1 week after birth. GMF-beta mRNA and protein were also observed in several cultured cells. Some cells of neural origin contained higher levels of GMF-beta protein compared with cells derived from other sources. Through demonstration of mRNA and confirmation by immunoblotting, we conclude that GMF-beta is synthesized by rat organs and that GMF-beta is predominantly a brain protein.
Zaheer
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A
Department of Neurology, Division of Neurochemistry and Neurobiology, University of Iowa College of Medicine, Iowa City 52242.
Fink
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BD
Lim
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R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D020904:Glia Maturation Factor; D006131:Growth Inhibitors / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D015345:Oligonucleotide Probes / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats / Q000378:metabolism*
D020904:Glia Maturation Factor; D006131:Growth Inhibitors; D009419:Nerve Tissue Proteins; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D004247:DNA