Detection of the peripheral nervous system (PNS)-type glial fibrillary acidic protein (GFAP) and its mRNA in human lymphocytes.
Glial fibrillary acidic protein (GFAP), an astroglial marker, has been detected in the peripheral nervous system (PNS) in a shorter version and its mRNA in a longer form (beta-type) than the brain alpha-type. To determine the characteristics of the GFAP gene expression in nonneural cells, we have investigated its in vivo transcription and translation products in human lymphocytes. Using RT-PCR, we demonstrate that the GFAP gene is transcribed in these cells. Most or all of the mRNA resulting from this transcription was longer than the brain-type at its 5' end and thus may correspond to the beta-type. In addition, immunoblotting of lymphocyte extracts with a monoclonal antibody revealed a 41 KDa fragment instead of the 50 KDa expected from brain GFAP. These results suggest that GFAP expression in lymphocytes is preferentially of the PNS beta-type giving rise to longer mRNA and shorter protein. However, compared to two other astroglial mRNAs (S-100beta and aldolase C) which were synthesized in significant amounts in lymphocytes, GFAP mRNA was detected in minute amounts representing 0.03% of the brain level. This low expression may subserve a special role in lymphocytes since it is translated.
Riol
H
H
Department of Biochemistry, Faculty of Medicine, Laval University, Quebec, Canada.
Tardy
M
M
Rolland
B
B
Lévesque
G
G
Murthy
M R
MR
D000911:Antibodies, Monoclonal; D001253:Astrocytes / Q000737:chemistry / Q000201:enzymology; D015153:Blotting, Western; D001923:Brain Chemistry / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000235:genetics; D005634:Fructose-Bisphosphate Aldolase / Q000032:analysis / Q000235:genetics; D015870:Gene Expression / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis* / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry* / Q000201:enzymology; D009414:Nerve Growth Factors; D017933:Peripheral Nervous System / Q000737:chemistry* / Q000201:enzymology; D012333:RNA, Messenger / Q000032:analysis; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000032:analysis / Q000235:genetics; D014158:Transcription, Genetic / Q000502:physiology
D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D005904:Glial Fibrillary Acidic Protein; D009414:Nerve Growth Factors; D012333:RNA, Messenger; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D005634:Fructose-Bisphosphate Aldolase