Abstract |
Previously, we showed that the transport of Cu by PC12 pheochromocytoma cells and C6 glioma cells correlated with the expression of a Cu-transporting ATPase (Atp7a) that has been linked to Menkes disease. Here, we show that cerebrovascular endothelial (CVE) cells that comprise the blood-brain barrier (BBB) also express the gene for the Cu- ATPase. By using reverse transcription-polymerase chain reaction (RT-PCR) and primers designed from mouse Atp7a cDNA, we amplified a 925-bp and a 760-bp cDNA fragment from two extreme regions of Atp7a mRNA from murine CVE cells; 777 bp of the 925-bp fragment and 677 bp of the 760-bp fragment had a 99.7 and 100% sequence homology, respectively, with mouse Atp7a cDNA. The 777-bp sequences covered the heavy metal binding (Hmb) domain and the 677-bp fragment coded for residues at the -COOH terminus of Atp7a. A functional analysis showed that Cu efflux was blocked by the sulfhydryl reagent p-chloromercuribenzoate (p-CMB), a potential inhibitor of Atp7a function. This study provides strong evidence that a Cu- ATPase in the BBB controls the penetration of Cu into the brain and that lesions to the Cu- ATPase in CVE cells are a primary cause of low brain Cu levels in Menkes disease.
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Authors | Y Qian, E Tiffany-Castiglioni, J Welsh, E D Harris |
Journal | The Journal of nutrition
(J Nutr)
Vol. 128
Issue 8
Pg. 1276-82
(Aug 1998)
ISSN: 0022-3166 [Print] United States |
PMID | 9687544
(Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Atp7a protein, mouse
- Carrier Proteins
- Cation Transport Proteins
- DNA, Complementary
- Recombinant Fusion Proteins
- Copper
- RNA-Directed DNA Polymerase
- Adenosine Triphosphatases
- Copper-Transporting ATPases
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Topics |
- Adenosine Triphosphatases
(chemistry, genetics, metabolism)
- Amino Acid Sequence
- Animals
- Base Sequence
- Biological Transport
- Blood-Brain Barrier
- Brain
(blood supply)
- Carrier Proteins
(chemistry, genetics, metabolism)
- Cation Transport Proteins
- Copper
(metabolism)
- Copper-Transporting ATPases
- DNA, Complementary
(chemistry)
- Endothelium, Vascular
(enzymology)
- Gene Expression
- Menkes Kinky Hair Syndrome
(enzymology)
- Mice
- Microcirculation
(enzymology)
- Molecular Sequence Data
- Polymerase Chain Reaction
- RNA-Directed DNA Polymerase
- Recombinant Fusion Proteins
- Sequence Homology
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