The objectives of this proposal are to identify and characterize novel proteins involved in mitochondrial iron/heme metabolism identified from differentiating fetal liver population by mRNA sequencing (RNAseq) and bioinformatics approaches. Heme serves as a prosthetic group in hemo-proteins for a wide array of crucial cellular processes, and of these, hemoglobin synthesis in red cells is the most well known. Despite advances in our understanding of cytosolic iron trafficking and proto-prophyrin biosynthesis, significant gaps remain, especially, with respect to components involving the egress of iron from the endosomes to the mitochondria, the trafficking of iron/heme within the mitochondria, and the eventual export of heme from the mitochondria for its incorporation in hemoglobin. In recent years, we have characterized the role ofthe l /litoferrin1 (l /lfrn1, Slc25a37) iron importer and its interaction with other mitochondrial proteins, AbcblO and ferrochelatase, in the acquisition of mitochondrial iron and its utilization in heme synthesis. In an attempt to dentify additional, unknown components important for heme synthesis, we screened thousands of microarrays for genes that were tightly co-expressed and co-regulated with previously known heme biosynthesis genes to identify potentially interesting, novel candidate genes. Follow up studies of these candidate genes in the zebrafish showed that gene-specific knockdown, using anti-sense morpholinos, resulted in profound anemia in all cases. In a complementary approach, we recently analyzed the expression of structural proteins with predicted transmembrane motifs, transporter function, or localization to the mitochondria, which were identified by RNAseq analysis from differentiating fetal liver cells. We identified 9 additional strongly induced genes, whose function in erythroid iron/heme metabolism has not been previously studied. We propose to study the expression and loss-of-function phenotype of these 9 structural genes (c20orf108, Snx3, Slc43a1, Slc43a3, Slc7a5, Ehbplll, Tmcc2, Slc38a5, Tmem14c) in the zebrafish and mammalian cells. In particular, we plan to focus on one of these newly identified genes from the two bioinformatics screens, Tmem14c, a small mitochondrial membrane protein of unknown function.
Elucidating the function of these 8 structural proteins, Tmem14c and its interacting protein partners may give insight into unknown steps in mitochondrial heme metabolism and provide new genetic tools for exploring human disorders of iron/heme metabolism and erythropoiesis.
|Huang, Jialiang; Liu, Xin; Li, Dan et al. (2016) Dynamic Control of Enhancer Repertoires Drives Lineage and Stage-Specific Transcription during Hematopoiesis. Dev Cell 36:9-23|
|Canver, Matthew C; Orkin, Stuart H (2016) Customizing the genome as therapy for the Î²-hemoglobinopathies. Blood 127:2536-45|
|Gao, Xiaofei; Lee, Hsiang-Ying; da Rocha, Edroaldo Lummertz et al. (2016) TGF-Î² inhibitors stimulate red blood cell production by enhancing self-renewal of BFU-E erythroid progenitors. Blood 128:2637-2641|
|Shi, Jiahai; Yuan, Bingbing; Hu, Wenqian et al. (2016) JAK2 V617F stimulates proliferation of erythropoietin-dependent erythroid progenitors and delays their differentiation by activating Stat1 and other nonerythroid signaling pathways. Exp Hematol 44:1044-1058.e5|
|Hagedorn, Elliott J; Cillis, Jennifer L; Curley, Caitlyn R et al. (2016) Generation of Parabiotic Zebrafish Embryos by Surgical Fusion of Developing Blastulae. J Vis Exp :|
|Yien, Yvette Y; Paw, Barry H (2016) A role for iron deficiency in dopaminergic neurodegeneration. Proc Natl Acad Sci U S A 113:3417-8|
|Nasrallah, Rabab; Fast, Eva M; Solaimani, Parham et al. (2016) Identification of novel regulators of developmental hematopoiesis using Endoglin regulatory elements as molecular probes. Blood 128:1928-1939|
|Masuda, Takeshi; Wang, Xin; Maeda, Manami et al. (2016) Transcription factors LRF and BCL11A independently repress expression of fetal hemoglobin. Science 351:285-9|
|CHARGE Consortium Hematology Working Group (2016) Meta-analysis of rare and common exome chip variants identifies S1PR4 and other loci influencing blood cell traits. Nat Genet 48:867-76|
|Gao, Xin; Wu, Tongyu; Johnson, Kirby D et al. (2016) GATA Factor-G-Protein-Coupled Receptor Circuit Suppresses Hematopoiesis. Stem Cell Reports 6:368-82|
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