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The role of cyclophilins in splicing
Cit, Zdeněk ; Půta, František (advisor) ; Novotný, Ivan (referee)
Splicing is a process essential for the proper functioning of eukaryotic cells. It is a complicated and highly dynamic process, participated by large numbers of proteins which perform diverse functions, either directly within the splicing complex, or sometimes outside of it. Among the proteins, which play an important role in splicing, are cyclophilins. Cyclophilins probably cause conformational changes in the other components of splicing complex. They can also maintain them in the desire conformation thereby they contribute to the dynamics of the spliceosome. This work provides an overview of cyclophilins, which were confirmed to participate on pre-mRNA splicing, and summarizes suggestions of possible functions that these proteins may perform.
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Structural characterisation of Prp45 and its interaction partners
Kulhánková, Lucie ; Novotný, Marian (advisor) ; Kostovčíková, Klára (referee)
Prp45 is a SNW protein that is part of a spliceosome and therefore participates in splicing of pre-mRNA into mRNA. In spliceosome Prp45 joins as part of NTC complex before splicing reactions. Prp45 has several known interactional partners (such as small subunit of U2AF, Cyp2, Prp5, Prp22, Clf1 and Cwc3). These proteins serve many functions in the spliceosome from stability to regulation of splicing reactions. Spliceosome consists of several dozens of proteins and several RNA and undergoes massive structural changes during executing its function. Until recently very little was known about the spliceosome structure; however, recent studies allow us to look at interaction network of this machine. In this work we focused on identification of both previously predicted and new interactional partners of Prp45. Using available spliceosome structures we aimed to describe these proteins structurally and functionally. Key words: splicing, Prp45, 3D struktura, spliceosome, binding partners
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Effect of SR-like proteins in maturation and transfer of mRNA to the cytoplasm
Hájková, Karolína ; Abrhámová, Kateřina (advisor) ; Staněk, David (referee)
Metazoan SR proteins is a group of proteins involved in splicing. They are RNA-biding proteins characterized by the presence of serine and arginine-rich domain. The yeast, Saccharomyces cerevisiae, encodes genes for proteins that are similar in amino acid composition and structure to the group of SR proteins and are therefore called SR-like proteins. There are three proteins with RS domain in yeast: Npl3, Gbp2 and Hrb1. These proteins have been shown to have many functions, including, in addition to splicing, quality control of spliced mRNAs and their export from the nucleus to the cytoplasm. This Bachelor's thesis will deal with these three yeast proteins and their role in splicing, export and degradation.
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Extraribosomal function of ribosomal proteins
Gredová, Alexandra ; Folk, Petr (advisor) ; Roučová, Kristina (referee)
Ribosomal proteins are important not only because they enable proteosynthesis, but also because of their functions outside of ribosome - in their extraribosomal functions. This thesis is mainly focused on the extraribosomal functions of higher eukaryotic ribosomal proteins. Specifically, it analyzes three ribosomal proteins, L13a, L22, and S3, which illustrate several aspects of extraribosomal functions. It discusses the mechanisms of action of these proteins and how they affect various levels of gene expression. Key words: extraribosomal function, L13a, L22, S3, p53, NF - κB, splicing
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Structural characterisation of Prp45 and its interaction partners
Kulhánková, Lucie ; Novotný, Marian (advisor) ; Kostovčíková, Klára (referee)
Prp45 is a SNW protein that is part of a spliceosome and therefore participates in splicing of pre-mRNA into mRNA. In spliceosome Prp45 joins as part of NTC complex before splicing reactions. Prp45 has several known interactional partners (such as small subunit of U2AF, Cyp2, Prp5, Prp22, Clf1 and Cwc3). These proteins serve many functions in the spliceosome from stability to regulation of splicing reactions. Spliceosome consists of several dozens of proteins and several RNA and undergoes massive structural changes during executing its function. Until recently very little was known about the spliceosome structure; however, recent studies allow us to look at interaction network of this machine. In this work we focused on identification of both previously predicted and new interactional partners of Prp45. Using available spliceosome structures we aimed to describe these proteins structurally and functionally. Key words: splicing, Prp45, 3D struktura, spliceosome, binding partners
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The influence of intron sequences on splicing effectivity in Saccharomyces cerevisiae
Oplová, Michaela ; Půta, František (advisor) ; Malcová, Ivana (referee)
Pre-mRNA splicing is a highly regulated cellular process. The tight cooperation of spliceosome and other splicing factors that enable pre-mRNA cis-elements interpretation results in precise pre-mRNA splicing regulation. Short conserved splicing sequences within introns represent an elementary and indispensable element for intron removal from primary transcript, yet they are not sufficient signals for efficient splicing events. Additional pre-mRNA features affect complex splicing regulation. We took advantage of strains with slightly disrupted spliceosome (prp45(1-169)) to study the effect of ACT1 and MAF1 intronic sequences on splicing efficiency. Here we show, that ACT1 intron region between branch point (BP) and 3' splice site (3'ss) maintains splicing efficiency in mutant cells. However, the specific element within this region was not determined. In addition, results implicate an alternative BP in splicing efficiency modulation in yeast Saccharomyces cerevisiae. Interestingly, this alternative BP is localized in ACT1 intron outside of the BP-3'ss region. Furthermore, splicing factors with potential influence on 3'ss selection were studied. Heterodimer composed of Slu7p and Prp18p participates in 3'ss positioning to the active site of the spliceosome. Splicing analysis of substrates with two...
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The role of cyclophilins in splicing
Cit, Zdeněk ; Půta, František (advisor) ; Novotný, Ivan (referee)
Splicing is a process essential for the proper functioning of eukaryotic cells. It is a complicated and highly dynamic process, participated by large numbers of proteins which perform diverse functions, either directly within the splicing complex, or sometimes outside of it. Among the proteins, which play an important role in splicing, are cyclophilins. Cyclophilins probably cause conformational changes in the other components of splicing complex. They can also maintain them in the desire conformation thereby they contribute to the dynamics of the spliceosome. This work provides an overview of cyclophilins, which were confirmed to participate on pre-mRNA splicing, and summarizes suggestions of possible functions that these proteins may perform.
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Structural and functional characterization of giant plant Ogre-like retrotransposons
STEINBAUEROVÁ, Veronika
Ogre elements represent a distinct group of Ty3/gypsy LTR retrotransposons occurring in a range of dicot plants. They are characterized by two specific features ? presence of long extra open reading frame in 5´ untranslated region with unknown function and a non-coding sequence containing several stop codons separating protease and reverse transcriptase domains which was proposed to be removed by splicing. This thesis describes the functional analysis of intron splicing in Ogre retrotransposons. Further, it investigates additional coding information not only in Ogre retrotransposons but in the whole group of Ty3/gypsy retroelements.
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