Disease relevance of ATMRP1

• All are members of the multidrug resistance-associated protein (MRP)/cystic fibrosis transmembrane conductance regulator (CFTR) subfamily of ATP-binding cassette (ABC) transporters [1].

High impact information on ATMRP1

• AtMRP2, an Arabidopsis ATP binding cassette transporter able to transport glutathione S-conjugates and chlorophyll catabolites: functional comparisons with Atmrp1 [2].
• AtMRP1 gene of Arabidopsis encodes a glutathione S-conjugate pump: isolation and functional definition of a plant ATP-binding cassette transporter gene [3].
• We show here that a transporter responsible for the removal of glutathione S-conjugates from the cytosol, a specific Mg2+-ATPase, is encoded by the AtMRP1 gene of Arabidopsis thaliana [3].
• The sequence of AtMRP1 and the transport capabilities of membranes prepared from yeast cells transformed with plasmid-borne AtMRP1 demonstrate that this gene encodes an ATP-binding cassette transporter competent in the transport of glutathione S-conjugates of xenobiotics and endogenous substances, including herbicides and anthocyanins [3].
• Unlike AtPGP1, AtMRP1 binds to the C-terminal tetratricopeptide repeat domain of TWD1, which is well known to mediate protein-protein interactions [4].

Biological context of ATMRP1

• ABC transporters from the multidrug resistance-associated protein (MRP) subfamily are glutathione S-conjugate pumps exhibiting a broad substrate specificity illustrated by numerous xenobiotics, such as anticancer drugs, herbicides, pesticides and heavy metals [5].

Anatomical context of ATMRP1

• We were able to demonstrate that TWD1 binds to isolated vacuoles and has a significant impact on the uptake of metolachlor-GS and estradiol-beta-glucuronide, well-known substrates of vacuolar transporters AtMRP1 and AtMRP2 [4].
• Expression of MRP1 at the plasma membrane was correlated with an increase in the MCPs resistance to Sb(III) and a limitation of the metalloid content in the protoplasts due to an improvement in Sb(III) efflux [5].

Associations of ATMRP1 with chemical compounds

• Moreover, Sb(III) transport was sensitive to classical inhibitors of the human MRP1, such as MK571 or glibenclamide [5].
• In order to investigate the functionality of MRP1 in Arabidopsis, mesophyll cell protoplasts (MCPs) were isolated from transgenic plants and transport activities were measured by using calcein or Sb(III) as substrates [5].

Other interactions of ATMRP1

• By membrane fractionation and GFP-tagging, we localized AtMRP1 to the central vacuolar membrane and the TWD1-AtMRP1 complex was verified in vivo by coimmunoprecipitation [4].
• AtMRP1, a multidrug resistance-associated (MRP/ABCC)-like ABC transporter, has been isolated in a yeast two-hybrid screen [4].

References