Expression of multiple mRNA species for choline acetyltransferase in human T-lymphocytes.
Acetylcholine (ACh) is synthesized by choline acetyltransferase (ChAT) in cholinergic neurons. However, both ACh and mRNA for ChAT are expressed in mononuclear leukocytes and various human leukemic T-cell lines. Multiple ChAT mRNA species (R-, N0-, N1-, N2-, and M-types) having an identical coding region and different 5'-noncoding regions have been discovered in human brain and spinal cord. These mRNAs are transcribed by a combination of use of different promoter regions and alternative splicing. However, which types of ChAT mRNA species are expressed in T-lymphocytes remains to be elucidated. In the present study, we used two human leukemic T-cell lines, CCRF-CEM (CEM) and MOLT-3, which express the same ChAT mRNA as that in the nervous system. Major mRNA species in CEM were N2- and M-type, and to a lesser extent N1-type, while MOLT-3 expressed only N2-type. Neither CEM nor MOLT-3 expressed R-type mRNA. We previously found a lack of mRNA expression encoding vesicular acetylcholine transporter (VAChT) in CEM and MOLT-3, which mediates ACh transport to synaptic vesicles in cholinergic neurons. These findings suggest that the mechanisms regulating ChAT mRNA expression in T-lymphocytes differ from those in cholinergic neurons.
Ogawa
Hiroshi
H
Department of Pharmacology, Kyoritsu College of Pharmacy, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan.
Fujii
Takeshi
T
Watanabe
Yoshihiro
Y
Kawashima
Koichiro
K
D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D002795:Choline O-Acetyltransferase / Q000096:biosynthesis* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D026901:Membrane Transport Proteins; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000378:metabolism*; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D010835:Phytohemagglutinins; D012333:RNA, Messenger; C493459:SLC18A3 protein, human; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D002795:Choline O-Acetyltransferase