linear polyubiquitin binding

Definition

Target type: molecularfunction

Binding to a linear polymer of ubiquitin. Linear ubiquitin polymers are formed by linking the amino-terminal methionine (M1) of one ubiquitin molecule to the carboxy-terminal glycine (G76) of the next. [GOC:bf, GOC:PARL, PMID:23453807]

Linear polyubiquitin chains are a specific type of ubiquitin modification that plays a crucial role in various cellular processes, including signal transduction, protein degradation, and DNA repair. They are distinct from the more common branched polyubiquitin chains, characterized by their unique head-to-tail linkage of ubiquitin monomers. This linear arrangement confers specific recognition and binding properties to proteins containing ubiquitin-binding domains (UBDs). Linear polyubiquitin binding is mediated by specialized UBDs, such as the linear ubiquitin binding domain (LUBD) or the ubiquitin-binding zinc finger (UBZ) domain. These domains exhibit high affinity and specificity for the linear ubiquitin chain topology. Upon binding, the linear polyubiquitin chain acts as a signal to recruit and activate downstream effector proteins, facilitating a cascade of events. For instance, in the context of NF-κB signaling, the LUBD-containing protein HOIP interacts with linear ubiquitin chains to assemble a complex that initiates downstream signaling pathways leading to the activation of NF-κB transcription factors. Similarly, in the context of DNA repair, the UBZ domain of the RNF8 protein recognizes linear ubiquitin chains at sites of DNA damage, enabling recruitment of DNA repair machinery. Overall, linear polyubiquitin binding serves as a crucial molecular mechanism to regulate various cellular processes by orchestrating the assembly of signaling complexes and recruitment of specific effector proteins. '
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Proteins (3)

Compounds (80)