Aheme transporter is aprotein that deliversheme to the various parts of abiological cell that require it.
Heme is a major source of dietary iron in humans and other mammals, and its synthesis in the body is well understood, but heme pathways are not as well understood. It is likely that heme is tightly regulated for two reasons: the toxic nature of iron in cells, and the lack of a regulated excretory system for excess iron. Understanding heme pathways is therefore important in understanding diseases such ashemochromatosis andanemia.
SLC48A1[2]—also known as Heme-Responsive Gene 1 (HRG1)—and itsorthologues were first identified as a heme transporter family through a genetic screen inC.elegans.[3] The protein plays a role in mobilizing heme from thelysosome to thecytoplasm.[4]Deletion of the gene in mice leads to accumulation of heme crystals calledhemozoin within the lysosomes of bone marrow, liver and splenic macrophages,[5][6] but the gene is not known to be associated with human disease.
FLVCR2[12] is closely related to FLCVR1, and genetictransfection experiments indicate that it transports heme.[13] Mutations in the gene are associated with proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome (PVHH, also known as Fowler syndrome).[14][15]
Related genes SLC49A3[16] and SLC49A4[17] are less well characterized[1] functionally, although SLC49A4 is also known as Disrupted In Renal Cancer Protein 2 or RCC4 due to an association withrenal cell cancer.[18][19]
^Keel SB, Doty RT, Yang Z, Quigley JG, Chen J, Knoblaugh S, Kingsley PD, De Domenico I, Vaughn MB, Kaplan J, Palis J, Abkowitz JL (February 2008). "A heme export protein is required for red blood cell differentiation and iron homeostasis".Science.319 (5864):825–8.Bibcode:2008Sci...319..825K.doi:10.1126/science.1151133.PMID18258918.S2CID5510704.
