beta2 knockout mice develop parenchymal iron overload: A putative role for class I genes of the major histocompatibility complex in iron metabolism.

AUTOR(ES)

Rothenberg, B E

RESUMO

Hemochromatosis (HC) is an inherited disorder of iron absorption, mapping within the human major histocompatibility complex (MHC). We have identified a multigene system in the murine MHC that contains excellent candidates for the murine equivalent of the human HC locus and implicate nonclassical class I genes in the control of iron absorption. This gene system is characterized by multiple copies of two head-to-head genes encoded on opposite strands and driven by one common regulatory motif. This regulatory motif has a striking homology to the promoter region of the beta-globin gene, a gene obviously involved in iron metabolism and hence termed beta-globin analogous promoter (betaGAP). Upstream of the betaGAP sequence are nonclassical class I genes. At least one of these nonclassical class I genes, Q2, is expressed in the gastrointestinal tract, the primary site of iron absorption. Also expressed in the gastrointestinal tract and downstream of the betaGAP motif is a second set of putative genes, termed Hephaestus (HEPH). Based on these observations, we hypothesized that the genes that seem to be controlled by the betaGAP regulatory motifs would be responsible for the control of Fe absorption. As a test of this hypothesis, we predicted that mice which have altered expression of class I gene products, the beta2-microglobulin knockout mice, [beta2m(-/-)], would develop Fe overload. This prediction was confirmed, and these results indicate beta2m-associated proteins are involved in the control of intestinal Fe absorption.

Documentos Relacionados

• Solution binding of an antigenic peptide to a major histocompatibility complex class I molecule and the role of beta 2-microglobulin.
• Gene knockout mice establish a primary protective role for major histocompatibility complex class II-restricted responses in Chlamydia trachomatis genital tract infection.
• Major histocompatibility complex class I genes of the coelacanth Latimeria chalumnae.
• A second lineage of mammalian major histocompatibility complex class I genes.
• Mice lacking major histocompatibility complex class I and class II molecules.