p-glycoproter is responsible for the drug resisting it is
encoded by the ABCB1 transporter it pumps the drugs to outside the cell which make
the drug concentration inside the cell much lower than the outside, as a result
it protects the cancer cell from the anticancer drugs.
over excerption of ABCB1 transporter causes multidrug
resistance(MDR1) which is responsible for making the resistance of drugs in the
This transporter Is
characterized by its high transporter capacity and its various wide substrate
its main function is to protect the cell by pumping the
toxic component or metabolite out of the cell, as a result it limits the entry
of the xenobiotic to the cell , it works in decreasing the drug
bioavailabilityby excreting the drug from the body by the excretion organs like
in the intestine epithelial cell where it pumps the drug to the intestinal
lumen and in the liver where it pumps the drug to the bile duct, and protect the
organs by decreasing the exposure of the cell to the toxic xenobiotic like in
blood brain barrier, testes and placenta.
it comes from the ATP binding cassette subfamily B member
Over view to ATP binding cassette B1 (BCB1):
the trance membrane domain binds to
the substrate and the nucleotide biding domains binds to the ATP molecule.
and tow nucleotide
binding domains located in the cytoplasm.
site called trance membrane domain locatedin the cell membrane
transporter consist of four domains,
The structure of ABC transporter:
ABC transporters are important in cellular lipid hemostasis
and it play an important role in control glucose and lipid metabolism by
control the secretion and activation of insulin and lipase.
ABC transporter is membrane protein that have the ability to
bind and hydrolyze of the ATP and use it as a source of energy to influx and efflux
the substrate out and in the cell.
The human ABC transporter have 48 members and seven subfamilies.
Over view to ATP binding cassata(ABC) transporter: