Proteasome-Independent Functions of Ubiquitin in Endocytosis and Signaling

  title={Proteasome-Independent Functions of Ubiquitin in Endocytosis and Signaling},
  author={Debdyuti Mukhopadhyay and Howard Riezman},
  pages={201 - 205}
Ubiquitination is a reversible posttranslational modification of cellular proteins, in which a 76–amino acid polypeptide, ubiquitin, is primarily attached to the ϵ-amino group of lysines in target proteins. Ubiquitination is a major player in regulating a broad host of cellular processes, including cell division, differentiation, signal transduction, protein trafficking, and quality control. Aberrations in the ubiquitination system are implicated in pathogenesis of some diseases, certain… 

The role of ubiquitylation for the control of cell death in Drosophila

  • A. Bergmann
  • Biology, Chemistry
    Cell Death and Differentiation
  • 2010
The role of ubiquitylation in the cell death pathway in Drosophila is reviewed and it is suggested that anti-apoptotic Ubiquitylation may involve, at least in part, non-proteolytic functions.

Seven-Transmembrane Receptors and Ubiquitination

This review highlights some of the recently discovered and provocative roles for ubiquitination in the regulation of the life cycle and signal transduction properties of 7-transmembrane receptors that serve to integrate many biological functions and play fundamental roles in cardiovascular homeostasis.

The Ubiquitin-Proteasome System in Apoptosis and Apoptotic Cell Clearance

The role of ubiquitination and deubiquitination in apoptosis and apoptotic cell clearance, one of the most well-studied forms of programmed cell death, is discussed.

Non-26S proteasome proteolytic role of ubiquitin in plant endocytosis and endosomal trafficking(F).

This review focuses on a summary and analysis of the recent research progress on Ub acting as a signal to mediate endocytosis and endosomal trafficking in plants.

p53 regulation by ubiquitin

Ubiquitin, the proteasome and protein degradation in neuronal function and dysfunction

The molecular mechanism of protein degradation in the neuron with respect to both its function and its dysfunction is discussed, highlighting the importance and vulnerability of the degradative system in neurons.

Targeting proteins for destruction by the ubiquitin system: implications for human pathobiology.

This review focuses on the response to hypoxia, inflammatory diseases, neurodegenerative diseases, and muscle-wasting disorders, as well as human papillomaviruses, cervical cancer and other malignancies.

Ubiquitin-binding proteins: decoders of ubiquitin-mediated cellular functions.

The combinatorial use of diverse ubiquitin-binding domains (UBDs) in full-length proteins, selective recognition of chains with distinct linkages and length, and posttranslational modifications of Ubiquitin receptors or multivalent interactions within protein complexes illustrate a few mechanisms by which a circuitry of signaling networks can be rewired by ubiquitIn-binding proteins to control cellular functions in vivo.

Proteomic identification of protein ubiquitination events

Mass-spectrometry-based methods for the identification of protein ubiquitination sites are discussed, their advantages and disadvantages are analyzed, and their application for proteomic analysis of ubiquitinated proteins is discussed.



Delivery of ubiquitinated substrates to protein-unfolding machines

The intimate interplay between the proteasome and Cdc48, mediated in part by loosely associated ubiquitin receptors, has important functions in cellular regulation.

Ubiquitin: structures, functions, mechanisms.

Ubiquitination on Nonlysine Residues by a Viral E3 Ubiquitin Ligase

It is found that MIR1, but not MIR2, promoted down-regulation of MHC I molecules lacking lysine residues in their intracytoplasmic domain, which means ubiquitination can occur on proteins lacking accessible lysines or an accessible N terminus.

Regulation of ubiquitin-binding proteins by monoubiquitination

It is demonstrated that monoubiquitination of the endocytic proteins Sts1, Sts2, Eps15 and Hrs results in intramolecular interactions between ubiquitin and their UBDs, thereby preventing them from binding in trans to ubiquitinated targets.

A ubiquitin-interacting motif protects polyubiquitinated Met4 from degradation by the 26S proteasome

Covalent attachment of ubiquitin to proteins regulates a host of cellular events by proteolysis dependent and independent mechanisms. A variety of protein domains that bind non-covalently to

Proteolysis-independent regulation of the transcription factor Met4 by a single Lys 48-linked ubiquitin chain

It is shown that a single ubiquitin chain is attached to Met4 through lysine at position 163, which supports a proteolysis-independent role of Cdc34–SCFMet30-catalysed Met4 ubiquitination, and suggests that Lys 48-linked ubiquit in chains can have a regulatory role independent of proteolytic activity.

Multiple monoubiquitination of RTKs is sufficient for their endocytosis and degradation

It is shown that the epidermal growth factor and platelet-derived growth factor receptors are not polyubiquitinated but rather are monoubiquitination at multiple sites after their ligand-induced activation and a single ubiquitin is sufficient for both receptor internalization and degradation.