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Functional Analysis Of The Caf1 Protein, Takbum Ohn

Doctoral Dissertations

The CAF1 protein is a component of the CCR4-NOT deadenylase complex. While yeast CAF1 displays deadenylase activity, this activity is not required for its function in vivo, and CCR4 is the primary deadenylase in the complex. In order to identify CAF1-specific functional regions required for deadenylation in vivo, we targeted for mutagenesis six regions of CAF1 that are specifically conserved among CAF1 orthologs. Defects in three regions of the CAF1 protein (residues 173-175, residues 255-257 and residues 340-342, alleles caf1-1, caf1-3 and caf1-6, respectively) were found to dramatically reduce the rate of deadenylation in vivo and to result in typical …

Analysis Of The Role Of Poly(A) -Binding Protein (Pab1) In The Mrna Degradation Process In Yeast, Gang Yao

Doctoral Dissertations

The mRNA deadenylation process influences multiple aspects of protein synthesis and is known to be the major factor controlling mRNA decay rates. My data demonstrates that yeast PAB1 plays both positive and negative roles in controlling deadenylation, and I have identified particular regions of PAB1 involved in controlling different aspects of the mRNA degradative process. I have found that yeast PAB1 does not play a simple, obstructionist role in regulating CCR4 deadenylation. Instead, PAB1-PAB1 protein interactions, as mediated by the PAB1 proline-rich region (P domain) and the RRM1 domain, are required for the CCR4 deadenylase activity. The P and RRM1 …

A Molecular And Morphological Investigation Of The Red Seaweed Genus Porphyra (Bangiales, Rhodophyta) In The Northwest Atlantic, Troy Lee Bray

Doctoral Dissertations

To evaluate the possible occurrence of cryptic Porphyra taxa in the Northwest Atlantic, extensive field collections were made during winter and spring periods when relatively few previous collections had been made. Approximately 100 different sites extending from Chance Harbor, New Brunswick, Canada to Rye, New York, USA, were sampled during multiple years (2001-2005). Historical specimens from several herbaria (NHA, FH, BM, WTU, MICH, US) were also examined for possible cryptic taxa. A combination of morphological and molecular tools was used to screen both recent and historical collections.

Sequences from the plastid-encoded, ribulose-1, 5-bisphosphate carboxylase-oxygenase large subunit (rbcL) gene and rbcL- …