title: Cancer-Related NEET Proteins Transfer 2Fe-2S Clusters to Anamorsin, a Protein Required for Cytosolic Iron-Sulfur Cluster Biogenesis.
abstract: Iron-sulfur cluster biogenesis is executed by distinct protein assembly systems. Mammals have two systems, the mitochondrial Fe-S cluster assembly system (ISC) and the cytosolic assembly system (CIA), that are connected by an unknown mechanism. The human members of the NEET family of 2Fe-2S proteins, nutrient-deprivation autophagy factor-1 (NAF-1) and mitoNEET (mNT), are located at the interface between the mitochondria and the cytosol. These proteins have been implicated in cancer cell proliferation, and they can transfer their 2Fe-2S clusters to a standard apo-acceptor protein. Here we report the first physiological 2Fe-2S cluster acceptor for both NEET proteins as human Anamorsin (also known as cytokine induced apoptosis inhibitor-1; CIAPIN-1). Anamorsin is an electron transfer protein containing two iron-sulfur cluster-binding sites that is required for cytosolic Fe-S cluster assembly. We show, using UV-Vis spectroscopy, that both NAF-1 and mNT can transfer their 2Fe-2S clusters to apo-Anamorsin with second order rate constants similar to those of other known human 2Fe-2S transfer proteins. A direct protein-protein interaction of the NEET proteins with apo-Anamorsin was detected using biolayer interferometry. Furthermore, electrospray mass spectrometry of holo-Anamorsin prepared by cluster transfer shows that it receives both of its 2Fe-2S clusters from the NEETs. We propose that mNT and NAF-1 can provide parallel routes connecting the mitochondrial ISC system and the CIA. 2Fe-2S clusters assembled in the mitochondria are received by NEET proteins and when needed transferred to Anamorsin, activating the CIA.
authors.affiliation: Departments of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, United States of America.
authors.forename: Colin H
authors.initials: CH
authors.lastname: Lipper
authors.affiliation: Departments of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, United States of America.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Paddock
authors.affiliation: Center for Theoretical Biological Physics and Department of Physics, Rice University, Houston, TX, 77005, United States of America.
authors.forename: José N
authors.initials: JN
authors.lastname: Onuchic
authors.affiliation: Department of Biology, University of North Texas, Denton, TX, 76203, United States of America.
authors.forename: Ron
authors.initials: R
authors.lastname: Mittler
authors.affiliation: The Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram, Jerusalem, 91904, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Nechushtai
authors.affiliation: Departments of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, United States of America.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Jennings
mesh_terms: D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D019281:Dimerization; D004579:Electron Transport; D006801:Humans; D007368:Interferometry; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001059:Apoproteins; C489114:CIAPIN1 protein, human; C525595:CISD1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D024101:Mitochondrial Proteins; C551999:NAF1 protein, human; D012261:Ribonucleoproteins