scholarly journals Human LINE-1 retrotransposition requires a metastable coiled coil and a positively charged N-terminus in L1ORF1p

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Elena Khazina ◽  
Oliver Weichenrieder
Keyword(s):  
Rna Binding ◽  
Coiled Coil ◽  
Genotypic Diversity ◽  
Sequence Evolution ◽  
Mammalian Evolution ◽  
Coiled Coil Domain ◽  
Coil Structure ◽  
Human Line ◽  
Membrane Fusion Proteins ◽  
Positively Charged

LINE-1 (L1) is an autonomous retrotransposon, which acted throughout mammalian evolution and keeps contributing to human genotypic diversity, genetic disease and cancer. L1 encodes two essential proteins: L1ORF1p, a unique RNA-binding protein, and L1ORF2p, an endonuclease and reverse transcriptase. L1ORF1p contains an essential, but rapidly evolving N-terminal portion, homo-trimerizes via a coiled coil and packages L1RNA into large assemblies. Here, we determined crystal structures of the entire coiled coil domain of human L1ORF1p. We show that retrotransposition requires a non-ideal and metastable coiled coil structure, and a strongly basic L1ORF1p amino terminus. Human L1ORF1p therefore emerges as a highly calibrated molecular machine, sensitive to mutation but functional in different hosts. Our analysis rationalizes the locally rapid L1ORF1p sequence evolution and reveals striking mechanistic parallels to coiled coil-containing membrane fusion proteins. It also suggests how trimeric L1ORF1p could form larger meshworks and indicates critical novel steps in L1 retrotransposition.

scholarly journals Structure and dynamics of the RNAPII CTDsome with Rtt103

2017 ◽  
Vol 114 (42) ◽  
pp. 11133-11138 ◽  
Author(s):  
Olga Jasnovidova ◽  
Tomas Klumpler ◽  
Karel Kubicek ◽  
Sergei Kalynych ◽  
Pavel Plevka ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Coiled Coil ◽  
Random Coil ◽  
Sequence Complexity ◽  
Structure And Dynamics ◽  
Coiled Coil Domain ◽  
Transcription Termination Factor ◽  
Coil Structure ◽  
Random Coil Structure ◽  
Long Rod

RNA polymerase II contains a long C-terminal domain (CTD) that regulates interactions at the site of transcription. The CTD architecture remains poorly understood due to its low sequence complexity, dynamic phosphorylation patterns, and structural variability. We used integrative structural biology to visualize the architecture of the CTD in complex with Rtt103, a 3′-end RNA-processing and transcription termination factor. Rtt103 forms homodimers via its long coiled-coil domain and associates densely on the repetitive sequence of the phosphorylated CTD via its N-terminal CTD-interacting domain. The CTD–Rtt103 association opens the compact random coil structure of the CTD, leading to a beads-on-a-string topology in which the long rod-shaped Rtt103 dimers define the topological and mobility restraints of the entire assembly. These findings underpin the importance of the structural plasticity of the CTD, which is templated by a particular set of CTD-binding proteins.

Coiled-coil domain-containing protein-124 (Ccdc124) is a novel RNA binding factor up-regulated in endometrial, ovarian, and urinary bladder cancers

2021 ◽  
pp. 1-16
Author(s):  
Özge Arslan ◽  
Neşe Karadağ Soylu ◽  
Pelin Telkoparan Akıllılar ◽  
Uygar H. Tazebay
Keyword(s):  
Urinary Bladder ◽  
Rna Binding ◽  
Functional Characterization ◽  
Coiled Coil ◽  
Protein Accumulation ◽  
Mrna Levels ◽  
Aberrant Expression ◽  
Mrna Targets ◽  
Coiled Coil Domain ◽  
Binding Factor

BACKGROUND: Coiled-coil domain containing protein-124 (Ccdc124) is a putative mRNA-binding factor associated with cell division, and ribosome biology. Previous reports mentioned an up-regulation of CCDC124 gene in cancer, and listed its mRNA in a molecular prognostic signature in breast cancer. OBJECTIVES: Establishing RNA-binding characteristics of Ccdc124 for a better molecular functional characterization, and carrying-out retrospective studies in order to evaluate its aberrant expression in human cancer samples from various tissue origins. METHODS: Bioinformatics calculations followed by RIP and RNA-seq experiments were performed to investigate mRNA targets of Ccdc124. Quantitative studies on arrays of cDNAs from different cancers and IHC assays on tissue arrays were used to assess CCDC124 expression levels in cancers. RESULTS: Ccdc124 was characterized as an RNA-binding protein (RBP) interacting with various mRNAs. CCDC124 mRNA levels were high in tumors, with a particular up-regulation in cancers from esophagus, adrenal gland, endometrium, liver, ovary, thyroid, and urinary bladder. IHC assays indicated strong Ccdc124 positivity in endometrial (95.4%), urinary bladder (68.4%), and ovarian cancers (86.8%). CONCLUSION: Ccdc124 is a cytokinesis related RBP interacting with various mRNAs. CCDC124 mRNA over-expression and an accompanied increase in Ccdc124 protein accumulation was reported in cancers, indicating this RBP as a novel cancer cell marker.

scholarly journals The clear and dark sides of water: influence on the coiled coil folding domain

2016 ◽  
Vol 7 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Tamás Vajda ◽  
András Perczel
Keyword(s):  
Water Molecule ◽  
Essential Role ◽  
Polypeptide Chain ◽  
Coiled Coil ◽  
Type Ii ◽  
Coiled Coil Domain ◽  
Coil Structure ◽  
Influence Of Water ◽  
The Stability

AbstractThe essential role of water in extra- and intracellular coiled coil structures of proteins is critically evaluated, and the different protein types incorporating coiled coil units are overviewed. The following subjects are discussed: i) influence of water on the formation and degradation of the coiled coil domain together with the stability of this conformer type; ii) the water’s paradox iii) design of coiled coil motifs and iv) expert opinion and outlook is presented. The clear and dark sides refer to the positive and negative aspects of the water molecule, as it may enhance or inhibit a given folding event. This duplicity can be symbolized by the Roman ‘Janus-face’ which means that water may facilitate and stimulate coiled coil structure formation, however, it may contribute to the fatal processes of oligomerization and amyloidosis of the very same polypeptide chain.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

scholarly journals The git5 Gβ and git11 Gγ Form an Atypical Gβγ Dimer Acting in the Fission Yeast Glucose/cAMP Pathway

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1159-1168 ◽  
Author(s):  
Sheila Landry ◽  
Charles S Hoffman
Keyword(s):  
Fission Yeast ◽  
Mammalian Cells ◽  
Glucose Repression ◽  
Coiled Coil ◽  
Carboxy Terminus ◽  
Amino Terminal ◽  
Camp Pathway ◽  
Coiled Coil Domain ◽  
Mutational Activation ◽  
Two Hybrid

AbstractFission yeast adenylate cyclase, like mammalian adenylate cyclases, is regulated by a heterotrimeric G protein. The gpa2 Gα and git5 Gβ are both required for glucose-triggered cAMP signaling. The git5 Gβ is a unique member of the Gβ family in that it lacks an amino-terminal coiled-coil domain shown to be essential for mammalian Gβ folding and interaction with Gγ subunits. Using a git5 bait in a two-hybrid screen, we identified the git11 Gγ gene. Co-immunoprecipitation studies confirm the composition of this Gβγ dimer. Cells deleted for git11 are defective in glucose repression of both fbp1 transcription and sexual development, resembling cells lacking either the gpa2 Gα or the git5 Gβ. Overexpression of the gpa2 Gα partially suppresses loss of either the git5 Gβ or the git11 Gγ, while mutational activation of the Gα fully suppresses loss of either Gβ or Gγ. Deletion of gpa2 (Gα), git5 (Gβ), or git11 (Gγ) confer quantitatively distinct effects on fbp1 repression, indicating that the gpa2 Gα subunit remains partially active in the absence of the Gβγ dimer and that the git5 Gβ subunit remains partially active in the absence of the git11 Gγ subunit. The addition of the CAAX box from the git11 Gγ to the carboxy-terminus of the git5 Gβ partially suppresses the loss of the Gγ. Thus the Gγ in this system is presumably required for localization of the Gβγ dimer but not for folding of the Gβ subunit. In mammalian cells, the essential roles of the Gβ amino-terminal coiled-coil domains and Gγ partners in Gβ folding may therefore reflect a mechanism used by cells that express multiple forms of both Gβ and Gγ subunits to regulate the composition and activity of its G proteins.

A Stutter in the Coiled-Coil Domain of Escherichia coli Co-chaperone GrpE Connects Structure with Function

Biochemistry ◽  
2021 ◽  
Author(s):  
Tulsi Upadhyay ◽  
Upasana S. Potteth ◽  
Vaibhav V. Karekar ◽  
Ishu Saraogi
Keyword(s):  
Escherichia Coli ◽  
Coiled Coil ◽  
Coiled Coil Domain
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