Differential and constitutive expression of neuronal, inducible, and endothelial nitric oxide synthase mRNAs and proteins in pathologically normal human tissues.
Nitric oxide (NO) is produced by NO synthases (nNOS, iNOS, and eNOS) expressed in various human tissues and depending on the amount of NO produced in each tissue, the physiological function of NO is determined. However, due to the difficulty in obtaining normal human tissues, little is known about the basal levels of each of the three NOS mRNAsand proteins expressed constitutively in various human tissues. Results of the present study indicate that the basal levels of each of the three NOS mRNAs and proteins expressed in various regions of brain and peripheral tissues are different both in their sizes and in their contents. In Northern blot analysis, two different-sized mRNAs were found for each NOS isozymes: for the nNOS, approximately 12 and <12 kb mRNAs; for the iNOS, 4.2 and 4.5 kb mRNAs; for the eNOS, 4.2 and 4.4 kb mRNAs. In the Western blot, several different-sized NOS proteins were detected ( approximately 160, approximately 140, and approximately 130 kDa for nNOS; approximately 130 kDa for iNOS and eNOS) with tissue-specific expression patterns. These differential expression patterns of NOS mRNAs and proteins were caused by alternative splicing in the open-reading frame, and 5'- and/or 3'-untranslated regions of NOS mRNAs. These results suggest that regulation for differential expression of the three NOS genes in various human tissues may occur by alternative splicing of the NOS mRNAs in tissue-specific patterns.
Park
C S
CS
Department of Pharmacology and Toxicology, Inha University, Inchon, Korea.
Krishna
G
G
Ahn
M S
MS
Kang
J H
JH
Chung
W G
WG
Kim
D J
DJ
Hwang
H K
HK
Lee
J N
JN
Paik
S G
SG
Cha
Y N
YN
D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D017398:Alternative Splicing / Q000235:genetics; D015153:Blotting, Western; D001921:Brain / Q000033:anatomy & histology / Q000196:embryology / Q000201:enzymology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000196:embryology / Q000201:enzymology; D008970:Molecular Weight; D019001:Nitric Oxide Synthase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D016366:Open Reading Frames / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D013154:Spleen / Q000201:enzymology
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D007527:Isoenzymes; D012333:RNA, Messenger; C496320:NOS1 protein, human; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III