Linked Life Data

11641397

Source:http://linkedlifedata.com/resource/pubmed/id/11641397

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
52
pubmed:dateCreated
2001-12-25
pubmed:databankReference
pubmed:abstractText
The NHE6 protein is a unique Na(+)/H(+) exchanger isoform believed to localize in mitochondria. It possesses a hydrophilic N-terminal portion that is rich in positively charged residues and many hydrophobic segments. In the present study, signal sequences in the NHE6 molecule were examined for organelle localization and membrane topogenesis. When the full-length protein was expressed in COS7 cells, it localized in the endoplasmic reticulum and on the cell surface. Furthermore, the protein was fully N-glycosylated. When green fluorescent protein was fused after the second (H2) or third (H3) hydrophobic segment, the fusion proteins were targeted to the endoplasmic reticulum (ER) membrane. The localization pattern was the same as that of fusion proteins in which green fluorescent protein was fused after H2 of NHE1. In an in vitro system, H1 behaved as a signal peptide that directs the translocation of the following polypeptide chain and is then processed off. The next hydrophobic segment (H2) halted translocation and eventually became a transmembrane segment. The N-terminal hydrophobic segment (H1) of NHE1 also behaved as a signal peptide. Cell fractionation studies using antibodies against the 15 C-terminal residues indicated that NHE6 protein localized in the microsomal membranes of rat liver cells. All of the NHE6 molecules in liver tissue possess an endoglycosidase H-resistant sugar chain. These findings indicate that NHE6 protein is targeted to the ER membrane via the N-terminal signal peptide and is sorted to organelle membranes derived from the ER membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49221-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11641397-Amino Acid Sequence, pubmed-meshheading:11641397-Animals, pubmed-meshheading:11641397-COS Cells, pubmed-meshheading:11641397-Cell Fractionation, pubmed-meshheading:11641397-Endoplasmic Reticulum, pubmed-meshheading:11641397-Green Fluorescent Proteins, pubmed-meshheading:11641397-Hepatocytes, pubmed-meshheading:11641397-Humans, pubmed-meshheading:11641397-Luminescent Proteins, pubmed-meshheading:11641397-Membrane Proteins, pubmed-meshheading:11641397-Microscopy, Fluorescence, pubmed-meshheading:11641397-Microsomes, Liver, pubmed-meshheading:11641397-Mitochondria, pubmed-meshheading:11641397-Molecular Sequence Data, pubmed-meshheading:11641397-Protein Isoforms, pubmed-meshheading:11641397-Protein Sorting Signals, pubmed-meshheading:11641397-Protein Structure, Secondary, pubmed-meshheading:11641397-Protein Transport, pubmed-meshheading:11641397-Rats, pubmed-meshheading:11641397-Recombinant Fusion Proteins, pubmed-meshheading:11641397-Secretory Vesicles, pubmed-meshheading:11641397-Sodium-Hydrogen Antiporter
pubmed:year
2001
pubmed:articleTitle
NHE6 protein possesses a signal peptide destined for endoplasmic reticulum membrane and localizes in secretory organelles of the cell.
pubmed:affiliation
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't