What is the function of ABC transporters?
ATP-binding cassette (ABC) transporters are a family of transporter proteins that contribute to drug resistance via ATP-dependent drug efflux pumps. P-glycoprotein (P-gp), encoded by the MDR1 gene, is an ABC transporter normally involved in the excretion of toxins from cells.
Do ABC transporters hydrolyze ATP?
(6,29−32) All ABC transporters share the same architecture, a dimer of two nucleotide-binding domains (NBDs) or ATP-binding cassettes (ABCs) that bind and hydrolyze ATP, and two transmembrane domains (TMDs) that provide the pathway for substrate translocation across the membrane.
What types of molecules are transported by ABC transporters?
While transport substrates of the rotary motor and P-type ATPases are, with few exceptions, limited to protons or metal ions, ABC transporters cover a wide spectrum of substrates, from small inorganic and organic molecules, such as amino acids, sugars, nucleosides, vitamins and metal clusters to larger organic …
Are ABC transporters primary active transport?
ABC transporters are primary active transporters, which transport a wide range of substrates mainly to the outside of a cell membrane or organelle.
Where are ABC transporters?
The ABC transporters comprise a large and multifunctional family of structurally related membrane proteins that are located in the plasma membrane of the cells or in the membrane of various cellular organelles.
What is an ABC transporter and how does it link antibiotic resistance and patient resistance to chemotherapeutic agents?
The ATP-binding cassette (ABC) transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis.
What is the ABC transport system?
The ABC (ATP binding cassette) transporter is one of the active transport systems of the cell, which is widespread in archaea, eubacteria, and eukaryotes (Higgins 1992). The ABC transporters form the largest group of paralogous genes in bacterial and archaeal genomes (Tatusov et al.
What is the function of ATP hydrolysis?
ATP hydrolysis provides the energy needed for many essential processes in organisms and cells. These include intracellular signaling, DNA and RNA synthesis, Purinergic signaling, synaptic signaling, active transport, and muscle contraction.
What distinguishes P type transporters from ABC transporters?
What distinguishes P-type transporters from ABC transporters? ATP hydrolysis by P-type transporters results in a phosphorylated intermediate while ATP hydrolysis causes ABC transporters to convert from an outward facing transporter to an inward facing transporter.
Where are ABC transporters located?
plasma membrane
The ABC transporters comprise a large and multifunctional family of structurally related membrane proteins that are located in the plasma membrane of the cells or in the membrane of various cellular organelles.
Are ABC transporters Antiporters?
MDR transporters can be divided into two classes based on their source of energy: Secondary transporters, which use proton gradients to facilitate an antiporter mechanism, and adenosine triphosphate (ATP) binding cassette (ABC) transporters that couple the hydrolysis of ATP to substrate transport across the cell …
Why are ABC transporters crucial to drug resistance?
ABCB1 has a crucial physiological function in these barriers, namely the protection of he cells and organs against toxic compounds and metabolites. Due to its high transport capacity and broad substrate recognition, this transporter can confer a multidrug resistance phenotype to cancer cells (see below).
What are ATP-binding cassette transporters in mitochondria?
A small number of physiologically important ATP-binding cassette (ABC) transporters are found in mitochondria. Most are half transporters of the B group forming homodimers and their topology suggests they function as exporters. The results of mutant studies point towards involvement in iron cofactor …
Is ABCG2 distributed in mitochondria a functional transporter?
Thus, it was found that ABCG2 distributed in mitochondria is a functional transporter and that the mitochondrial ABCG2 regulates ALA-mediated PpIX level through PpIX export from mitochondria to the cytosol. Publication types Research Support, Non-U.S. Gov’t
Is ABCG2 involved in 5-aminolevulinic acid-mediated protoporphyrin IX accumulation?
Mitochondrial localization of ABC transporter ABCG2 and its function in 5-aminolevulinic acid-mediated protoporphyrin IX accumulation Accumulation of protoporphyrin IX (PpIX) in malignant cells is the basis of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy.