Date of Degree
The nuclear pore complexes (NPCs) are large multi-protein channels that traverse the nuclear envelope and mediate nucleo-cytoplasmic transport. Proteomic studies have revealed that NPCs are composed of about thirty different proteins called nucleoporins. I explored a particular nucleoporin, Nup211, in fission yeast. nup211 is an essential gene; its deletion is lethal and causes morphological defects. In this study, I characterized the cell morphological defects caused by the down-regulation of Nup211 and found that restoring the N-terminal domain of Nup211 was sufficient to rescue the lethal phenotype and partially suppress the morphological defects. Additionally, I investigated the role Nup211 plays in cytokinesis. RNA-Sequencing analysis revealed that Nup211 down-regulation and overexpression elicited a global change in gene expression. Specifically in Nup211-down-regulated cells, there was a decrease in ace2 gene expression and its downstream targets- adg1, adg2, adg3, mid2, cfh4, eng1, agn1 and rgf3. ace2 and its target genes play a dominant role in normal septum formation, dissolution, and cell separation (cytokinesis). I show that directly restoring ace2 expression significantly suppressed the morphological defects caused by Nup211 down-regulation. These results suggest that Nup211 partially controls cytokinesis through control the expression of ace2. Furthermore, we identified proteins important for cytokinesis, such as actin, were affected by Nup211 down-regulation. Taken together, our data indicate that Nup211 is fundamental for fission yeast cell shape maintenance, cytokinesis and global gene expression.
Sookdeo, Ayisha R., "Nuclear Pore Protein Nup211 Is Essential for Cell Cycle Progression and Cell Shape Maintenance in Fission Yeast" (2015). CUNY Academic Works.