Biomaterial Database

Neuronal isoform of nitric oxide synthase is expressed at low levels in human retina. 1996

C S Park, and C Gianotti, and R Park, and G Krishna

Section of Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1760, USA.

1. The expression of neuronal isoform of nitric oxide synthase (nNOS) was studied in human retinal tissues. The cDNA sequence was cloned in human retinal poly (A)+ RNA by the RT-PCR method and encompassed an open-reading frame of 4,302 bp encoding 1,434 amino acids. This sequence showed a possibility of genetic polymorphism in comparison to human brain form. 2. Restriction fragment length polymorphism (RFLP) patterns of a partial cDNA fragment suggest that there is genetic polymorphism in the neuronal form of NOS. Important differences were observed in a certain region between human retinal and brain froms. This region is a result of frame shift by the addition of three cytidines. In this study, regions from human brain (cerebellum) and skeletal muscle as well as retina were sequenced to confirm the difference in this region. The sequences from these tissues were completely identical. This indicated that genetic polymorphism of nNOS gene was due to single base substitution and not frame shift phenomenon by addition or deletion of bases. 3. The nNOS mRNA of approximately 12 kb was detected by northern blot analysis. The lower level of the expression was distinguished in comparison to those of human brain and skeletal muscle. The cDNA transiently transfected into CHO-K1 cells expressed a protein which contained a significant level of NOS activity. The size of the nNOS was found to be approximately 160 kDa by both in vitro and in vivo translation systems. This NOS was calcium dependent and the K(m) for arginine was 4.4 microM. 4. The Ca+2, L-arginine and NADPH dependency along with the inhibitory effect of N-nitro-L-arginine on NOS activity were evaluated. The finding of a constitutive from of NOS in human retina, which is calcium-NADPH dependent, gives further credence to the possible role of nitric oxide in retinal function and neuronal diseases.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D011993	Recombinant Fusion Proteins	Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.	Fusion Proteins, Recombinant,Recombinant Chimeric Protein,Recombinant Fusion Protein,Recombinant Hybrid Protein,Chimeric Proteins, Recombinant,Hybrid Proteins, Recombinant,Recombinant Chimeric Proteins,Recombinant Hybrid Proteins,Chimeric Protein, Recombinant,Fusion Protein, Recombinant,Hybrid Protein, Recombinant,Protein, Recombinant Chimeric,Protein, Recombinant Fusion,Protein, Recombinant Hybrid,Proteins, Recombinant Chimeric,Proteins, Recombinant Fusion,Proteins, Recombinant Hybrid
D012150	Polymorphism, Restriction Fragment Length	Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.	RFLP,Restriction Fragment Length Polymorphism,RFLPs,Restriction Fragment Length Polymorphisms
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
D002531	Cerebellum	The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.	Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D003412	Cricetulus	A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.	Hamsters, Armenian,Hamsters, Chinese,Hamsters, Grey,Armenian Hamster,Armenian Hamsters,Chinese Hamster,Chinese Hamsters,Grey Hamster,Grey Hamsters,Hamster, Armenian,Hamster, Chinese,Hamster, Grey
D005136	Eye Proteins	PROTEINS derived from TISSUES of the EYE.	Proteins, Eye