Digital Commons Network^™

The Enzymatic Function Of The Ccr4 Protein, Junji Chen

Doctoral Dissertations

The CCR4-NOT complex from Saccharomyces cerevisiae, which exists in two forms in vivo: 1.9 and 1.0 x 10 6 MDa in size, is a general transcriptional regulatory complex. It regulates mRNA transcription in initiation, elongation and degradation.

The 1.0 MDa complex was purified to near homogeneity, and mass spectrometric analysis was used to identify all the components of the complex. The 1.0 MDa complex contains CCR4, CAF1, NOT1--5, and two new proteins, CAF40 and CAF130. CAF130 and CAF40 are two unique yeast proteins, with CAF40 displaying extensive homology to proteins from other eukaryotes. Immunoprecipitation and gel filtration experiments confirm that …

Identification Of Suppressors Of Spt10 That Affect Adh2 Expression In The Yeast Saccharomyces Cerevisiae, Bradley David Anderson

Doctoral Dissertations

Suppression of the effects of an spt10 mutation on ADH2 expression is a phenotype shared by a small number of genes involved in the regulation of gene expression. All six known suppressors of spt10 are either components of the CCR4-NOT Complex (CCR4, CAF1, NOT4), or have been shown to interact with the complex ( DBF2, SRB9, SRB10). This indicated that spt10 suppression may be characteristic of CCR4-like gene regulation. In this work, I conducted a screen for additional suppressors of spt10 at ADH2. The screen identified no less than ten complementation groups, including ADH2 and two known suppressors of spt10, …

The Relationship Between Fruit Color Traits And Anthocyanin Genes In Diploid Fragaria, Chaoyang Deng

Doctoral Dissertations

A candidate gene approach was used to determine the likely molecular identity of the c locus (yellow fruit color) in Fragaria vesca, a diploid (2n = 2x = 14) strawberry. Using PCR with degenerate primer pairs, intron-containing segments of structural genes coding for the enzymes: chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanindin synthase (ANS), and one Del-like regulatory gene (RAN) in the anthocyanin biosynthetic pathway were amplified, cloned and sequenced. Intron length polymorphisms for each of these genes were detected among three diploid varieties: F. vesca Alpine variety 'Yellow Wonder' (YW) (Europe); DNIC, an …

Regulation Of Mammalian Photoreceptor Phosphodiesterase (Pde) By Its Noncatalytic Gaf Domains And Its Two Small Subunits, Gamma And Delta, Hongmei Mou

Doctoral Dissertations

cGMP phosphodiesterase (PDE) is the central effector of visual transduction in retinal rod photoreceptors. The overall goal of this work was to investigate the possible regulatory mechanisms of PDE in mammalian rod photoreceptors by its noncatalytic cGMP binding sites on the PDE catalytic dimer (Palphabeta), and by the interactions between the inhibitory Pgamma subunit and Palphabeta in their phosphorylated and non-phosphorylated states.

First, the binding of cGMP to the noncatalytic sites on membrane-associated PDE (PDE-M) and soluble PDE (PDE-S) was characterized. We found that PDE-M holoenzyme contains 2 non-identical high-affinity cGMP binding sites; one of the cGMP binding sites is …