Geir Bjørkøy

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Protein degradation by basal constitutive autophagy is important to avoid accumulation of polyubiquitinated protein aggregates and development of neurodegenerative diseases. The polyubiquitin-binding protein p62/SQSTM1 is degraded by autophagy. It is found in cellular inclusion bodies together with polyubiquitinated proteins and in cytosolic protein(More)
Autophagic degradation of ubiquitinated protein aggregates is important for cell survival, but it is not known how the autophagic machinery recognizes such aggregates. In this study, we report that polymerization of the polyubiquitin-binding protein p62/SQSTM1 yields protein bodies that either reside free in the cytosol and nucleus or occur within(More)
Autophagy is a catabolic process where cytosolic cellular components are delivered to the lysosome for degradation. Recent studies have indicated the existence of specific receptors, such as p62, which link ubiquitinated targets to autophagosomal degradation pathways. Here we show that NBR1 (neighbor of BRCA1 gene 1) is an autophagy receptor containing LC3-(More)
Autophagy is the main eukaryotic degradation pathway for long-lived proteins, protein aggregates, and cytosolic organelles. Although the protein machinery involved in the biogenesis of autophagic vesicles is well described, very little is known about the mechanism of cytosolic transport of autophagosomes. In this study, we have identified an adaptor protein(More)
The Phox and Bem1p (PB1) domain constitutes a recently recognized protein-protein interaction domain found in the atypical protein kinase C (aPKC) isoenzymes, lambda/iota- and zeta PKC; members of mitogen-activated protein kinase (MAPK) modules like MEK5, MEKK2, and MEKK3; and in several scaffold proteins involved in cellular signaling. Among the last(More)
Autophagy is an evolutionarily conserved pathway responsible for degradation of cytoplasmic material via the lysosome. Although autophagy has been reported to contribute to cell death, the underlying mechanisms remain largely unknown. In this study, we show that autophagy controls DNA fragmentation during late oogenesis in Drosophila melanogaster.(More)
The p62 protein, also called sequestosome 1 (SQSTM1), is a ubiquitin-binding scaffold protein that colocalizes with ubiquitinated protein aggregates in many neurodegenerative diseases and proteinopathies of the liver. The protein is able to polymerize via an N-terminal PB1 domain and can interact with ubiquitinated proteins via the C-terminal UBA domain.(More)
p62, also known as sequestosome1 (SQSTM1), A170, or ZIP, is a multifunctional protein implicated in several signal transduction pathways. p62 is induced by various forms of cellular stress, is degraded by autophagy, and acts as a cargo receptor for autophagic degradation of ubiquitinated targets. It is also suggested to shuttle ubiquitinated proteins for(More)
Autophagy is a physiological and evolutionarily conserved process maintaining homeostatic functions, such as protein degradation and organelle turnover. Accumulating data provide evidence that autophagy also contributes to cell death under certain circumstances, but how this is achieved is not well known. Herein, we report that autophagy occurs during(More)
Accumulation of ubiquitinated proteins in cytoplasmic and/or nuclear inclusions is a hallmark of several diseases associated with premature cell death. SQSTM1/p62 is known to bind ubiquitinated substrates and aid their aggregation and degradation by macroautophagy. We show here that p62 is required to recruit the large phosphoinositide-binding protein ALFY(More)