Apolipoprotein E: cholesterol transport protein with expanding role in cell biology

Science ◽  
1988 ◽  
Vol 240 (4852) ◽  
pp. 622-630 ◽  
Author(s):  
R. Mahley
Keyword(s):  
Apolipoprotein E ◽  
Cell Biology ◽  
Transport Protein ◽  
Cholesterol Transport

Apolipoprotein E gene and Alzheimer's disease: is tau the link?

2001 ◽  
Vol 67 ◽  
pp. 111-120 ◽  
Author(s):  
Simon Lovestone ◽  
Brian Anderton ◽  
Joanna Betts ◽  
Rejith Dayanandan ◽  
Graham Gibb ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Apolipoprotein E ◽  
Significant Advance ◽  
Cholesterol Transport ◽  
Vascular Risk ◽  
Polymorphic Variation ◽  
Gene Encoding ◽  
Single Mechanism ◽  
Apolipoprotein E Gene

The finding that APOE (the gene encoding apolipoprotein E) polymorphic variation was associated with an altered risk of developing Alzheimer's disease (AD) was a significant advance and immediately prompted a search for the mechanisms responsible for this alteration. Some 6 years later, a number of different hypotheses remain that might account for this influence on pathogenesis with no single mechanism being unequivocally accepted. The different approaches to understanding these mechanisms can be broadly categorized as: those suggesting a remote effect, such as different rates of vascular risk factors in those with the different APOE alleles; those proposing altered neuronal vulnerability, perhaps due to apolipoprotein E (ApoE)-isoform-specific differences in local cholesterol transport; and those hypotheses postulating an ApoE interaction with the two key lesions of AD, plaques and tangles. In this chapter we will review the evidence for and against an interaction between ApoE and the neuronal cytoskeleton, in particular with the microtubule-associated protein tau.

Ion homeostasis, channels, and transporters: an update on cellular mechanisms

2004 ◽  
Vol 28 (4) ◽  
pp. 143-154 ◽  
Author(s):  
George R. Dubyak
Keyword(s):  
Ion Channels ◽  
Subcellular Localization ◽  
Ion Transport ◽  
Membrane Transport ◽  
Cell Biology ◽  
Functional Characterization ◽  
Transport Proteins ◽  
Transport Protein ◽  
Membrane Transport Proteins ◽  
Functional Analyses

The steady-state maintenance of highly asymmetric concentrations of the major inorganic cations and anions is a major function of both plasma membranes and the membranes of intracellular organelles. Homeostatic regulation of these ionic gradients is critical for most functions. Due to their charge, the movements of ions across biological membranes necessarily involves facilitation by intrinsic membrane transport proteins. The functional characterization and categorization of membrane transport proteins was a major focus of cell physiological research from the 1950s through the 1980s. On the basis of these functional analyses, ion transport proteins were broadly divided into two classes: channels and carrier-type transporters (which include exchangers, cotransporters, and ATP-driven ion pumps). Beginning in the mid-1980s, these functional analyses of ion transport and homeostasis were complemented by the cloning of genes encoding many ion channels and transporter proteins. Comparison of the predicted primary amino acid sequences and structures of functionally similar ion transport proteins facilitated their grouping within families and superfamilies of structurally related membrane proteins. Postgenomics research in ion transport biology increasingly involves two powerful approaches. One involves elucidation of the molecular structures, at the atomic level in some cases, of model ion transport proteins. The second uses the tools of cell biology to explore the cell-specific function or subcellular localization of ion transport proteins. This review will describe how these approaches have provided new, and sometimes surprising, insights regarding four major questions in current ion transporter research. 1) What are the fundamental differences between ion channels and ion transporters? 2) How does the interaction of an ion transport protein with so-called adapter proteins affect its subcellular localization or regulation by various intracellular signal transduction pathways? 3) How does the specific lipid composition of the local membrane microenvironment modulate the function of an ion transport protein? 4) How can the basic functional properties of a ubiquitously expressed ion transport protein vary depending on the cell type in which it is expressed?

Impact of Aging on Cholesterol Transport Protein Expression and Steroidogenesis in Rat Testicular Leydig Cells

2008 ◽  
Vol 2 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Zhihong Sun ◽  
Wen-Jun Shen ◽  
Susan-Leers Sucheta ◽  
Salman Azhar
Keyword(s):  
Protein Expression ◽  
Leydig Cells ◽  
Transport Protein ◽  
Cholesterol Transport
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