Year: 2009
Type: dissertation
Abstract: Nvj1 is an interesting yeast protein that is part of the only known apparatus for interorganelle contact, the nucleus-vacuole (NV) junction. NV junctions are essential for a novel form of autophagy known as piecemeal microautophagy of the nucleus (PMN). During PMN, both the inner nuclear membrane (INM) and the outer nuclear membrane (ONM) exvaginate into the vacuole, delivering a non-essential portion of the nucleus for degradation. The N-terminus of Nvj1 is required for strict localization to the perinuclear endoplasmic reticulum (ER). In this study I present evidence that the N-terminus of Nvj1 is anchored in the INM through a combination of a hydrophobic stretch of amino acids and flanking basic residues. To help assess genetic, physiological and environmental factors that affect PMN I developed a quantitative immunoblot assay that measures PMN throughput. To address the nature of the interaction that occurs between the Nvj1 N-terminus and the INM, I present data showing that several INM proteins do not play a role in anchoring Nvj1 to the INM. Furthermore, I show that these INM proteins are not required for efficient PMN. Our current working hypothesis is that the Nvj1 membrane anchor inserts directly into the lipid bilayer of the INM.
Authors: Millen, Jonathan I. (1979 - ), Goldfarb, David S.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: National Science Foundation
OpenAlex ID: W101905281