title: Dissecting Fission Yeast Shelterin Interactions via MICro-MS Links Disruption of Shelterin Bridge to Tumorigenesis.
abstract: Shelterin, a six-member complex, protects telomeres from nucleolytic attack and regulates their elongation by telomerase. Here, we have developed a strategy, called MICro-MS (Mapping Interfaces via Crosslinking-Mass Spectrometry), that combines crosslinking-mass spectrometry and phylogenetic analysis to identify contact sites within the complex. This strategy allowed identification of separation-of-function mutants of fission yeast Ccq1, Poz1, and Pot1 that selectively disrupt their respective interactions with Tpz1. The various telomere dysregulation phenotypes observed in these mutants further emphasize the critical regulatory roles of Tpz1-centered shelterin interactions in telomere homeostasis. Furthermore, the conservation between fission yeast Tpz1-Pot1 and human TPP1-POT1 interactions led us to map a human melanoma-associated POT1 mutation (A532P) to the TPP1-POT1 interface. Diminished TPP1-POT1 interaction caused by hPOT1-A532P may enable unregulated telomere extension, which, in turn, helps cancer cells to achieve replicative immortality. Therefore, our study reveals a connection between shelterin connectivity and tumorigenicity.
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
authors.forename: Jinqiang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697-4560, USA.
authors.forename: Clinton
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
authors.forename: Xichan
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
authors.forename: Jin-Kwang
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Bierma
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
authors.forename: Hyun-Ik
authors.initials: HI
authors.lastname: Jun
authors.affiliation: Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Rychnovsky
authors.affiliation: Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697-4560, USA.
authors.forename: Lan
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA. Electronic address: qiao@uci.edu.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiao
mesh_terms: D000626:Aminopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D063646:Carcinogenesis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D057057:Serine Proteases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000089804:Shelterin Complex; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019098:Telomerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016615:Telomere; D059505:Telomere Homeostasis; D034501:Telomere-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C529647:Ccq1 protein, S pombe; D004268:DNA-Binding Proteins; C440849:POT1 protein, human; C529645:Poz1 protein, S pombe; C509571:Rap1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; C529646:Tpz1 protein, S pombe; C499082:pot1 protein, S pombe; C104344:taz1 protein, S pombe; D019098:Telomerase; D057057:Serine Proteases; D000626:Aminopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases