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dc.contributor.authorTcherepanova, Irina Yurievna
dc.identifier.citationSource: Dissertation Abstracts International, Volume: 58-01, Section: B, page: 7500.;Advisors: Charles S. Rubin.
dc.description.abstractThe C. elegans gene encoding protein kinase C1A (PKC1A) is a component of an operon. A contiguous upstream gene (kup-1), which encodes a novel 45 kDa protein, is co-transcribed with PKC1A under the regulation of a single promoter/enhancer region. I investigated an interaction between the two products of the operon.;The kup-1/PKC1A promoter/enhancer was cloned and sequenced and its activity was studied in situ. Kup-1/PKC1A promoter activity is evident in virtually every somatic cell in the nematode. However, promoter activity is precisely activated and inactivated in unique patterns in subsets of C. elegans cells at various stages of embryonic, larval and adult development.;Affinity purified anti-KUP-1 IgGs revealed that KUP-1 polypeptide is expressed at all developmental stages, with the highest level detected in L1 and L2 larvae. It accumulates in nuclei of all somatic cells in C. elegans. Properties of KUP-1 were explored further in permanently transfected hamster AV12664 cells. As in intact C. elegans, KUP-1 was efficiently targeted to the nucleus in those cells. However, co-expression of PKC1A elicited a dramatic re-distribution of KUP-1 into an extra-nuclear compartment. In addition I demonstrated that KUP-1 localizes to a structure that appears to interact with coiled bodies and a novel organelle, named Gem (Liu and Dryfuss, 1996). We speculate that KUP-1 might be involved in splicing and pre-mRNA processing, as proposed for other components in Gems and coiled bodies.;Although, KUP-1 is a good substrate for certain PKC isoforms, it is not phosphorylated by PKC1A. Therefore, it is possible that PKC1A controls KUP-1 location and function via phosphoproteins that interact with KUP-1. I have identified two KUP-1 binding proteins (KBP) using the yeast 2-hybrid system. Partial sequencing of the KBP cDNA did not reveal homologies with proteins in the databases. However, the cloned cDNAs are homologous to each other, thereby allowing mapping of a putative KUP-1 binding site.;Mammalian Ca{dollar}\sp{lcub}2+{rcub}{dollar}-dependent PKCs {dollar}\alpha,\beta{dollar} and {dollar}\gamma{dollar} differ in their biochemical properties and subcellular localization. PKC2 is the only Ca{dollar}\sp{lcub}2+{rcub}{dollar}-dependent PKC in C. elegans. However several pkc-2 gene products are generated by differential splicing/promoter utilization (Isals-Trejo, in press). I demonstrated that three PKC2 isoforms are generated by differential promoter utilization. C. elegans transgenic lines that carry that lacZ reporter gene downstream from the three putative promoters were produced. Each putative promoter activated transcription in vivo and had a characteristic expression pattern. Expression patterns determined from these experiments agreed with the distribution pattern of PKC2 polypeptides obtained by immunofluorescence studies on intact C. elegans using anti-PKC2 IgGs.
dc.publisherProQuest Dissertations & Theses
dc.subjectMolecular biology.
dc.titleCharacterization of the interaction between products of a Caenorhabditis elegans operon: PKC1 and KUP-1

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