Spatial Organization and Molecular Interactions of the Schizosaccharomyces pombe Ccq1–Tpz1–Poz1 Shelterin Complex. Issue 19 (15th September 2017)

• Record Type: Journal Article
• Authors: Scott, Harry; Kim, Jin-Kwang; Yu, Clinton; Huang, Lan; Qiao, Feng; Taylor, Derek J.
• Is Part Of: Journal of molecular biology. Volume 429:Issue 19(2017)
• Page Start: 2863
• Page End: 2872
• Publication Date: 2017-09-15
• Subjects: ssDNA single-stranded deoxyribonucleic acid -- dsDNA double-stranded deoxyribonucleic acid -- MBP maltose-binding protein -- ACD adrenocortical dysplasia -- TIN2 TRF1-interacting nuclear factor 2 -- CLRC Clr4 methyltransferase complex -- CTD C-terminal domain -- NTD N-terminal domain -- Ccq1 coiled-coil quantitatively enriched protein 1 -- Tpz1 protection of telomeres protein Tpz1 -- Poz1 protection of telomeres Poz1 -- Taz1 telomere length regulator Taz1 -- Est1 telomere elongation protein Est1 -- Rad3 DNA repair helicase Rad3 -- Tel1 serine/threonine protein kinase Tel1 -- Ccd13 cell-division control protein 13 -- Stn1 CST complex subunit Stn1 -- EM electron microscopy -- DSSO disuccinimidyl sulfoxide -- MICro-MS mapping interfaces via crosslinking mass spectrometry; telomere -- telomerase -- extension -- protection -- electron microscopy; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2017.08.002
• Languages: English
• ISSNs: 0022-2836

Abstract

Abstract: The shelterin complex is a macromolecular assembly of proteins that binds to and protects telomeric DNA, which composes the ends of all linear chromosomes. Shelterin proteins prevent chromosome ends from fusing together and from eliciting erroneous induction of DNA damage response pathways. In addition, shelterin proteins play key roles in regulating the recruitment and activation of telomerase, an enzyme that extends telomeric DNA. In fission yeast, Schizosaccharomyces pombe, interactions between the shelterin proteins Ccq1, Tpz1, and Poz1 are important for regulating telomerase-mediated telomere synthesis and thus telomere length homeostasis. Here, we used electron microscopy combined with genetic labeling to define the three-dimensional arrangement of the S. pombe Ccq1–Tpz1–Poz1 (CTP) complex. Crosslinking mass spectrometry was used to identify individual residues that are in proximity to the protein–protein interfaces of the assembled CTP complex. Together, our data provide a first glimpse into the architectural design of the CTP complex and reveals unique interactions that are important in maintaining the S. pombe telomere in a non-extendible state. Graphical Abstract: Highlights: The CTP complex coordinates extension and protection in S. pombe . The CTP complex is a dimer of trimers. 34-Å resolution model of the CTP complex, solved by negative-stain EM. CTP subunit locations described. MICro-MS identifies unique interactions between Ccq1–Poz1 and supports Ccq1 CTD dimerization.