kinetochorami

Kinetochorami is a proposed class of kinetochore-associated proteins implicated in linking centromeric chromatin to microtubule attachment sites during cell division. The term has appeared in the scientific literature since the mid-2010s to describe a subcomponent of the kinetochore involved in stabilizing microtubule–kinetochore interfaces and in tension sensing.

Molecular characteristics: Kinetochorami are typically small to medium-sized, often rich in coiled-coil domains, and are thought to participate in dynamic interactions within the inner kinetochore. They are reported to associate with core KMN network components, including the Ndc80 complex and related scaffolds, forming a reversible network that reinforces microtubule attachments.

Functional role: They are proposed to contribute to the maturation and maintenance of kinetochore–microtubule connections, regulate attachment stability during microtubule dynamics, and participate in error-correction pathways by modulating phospho-signaling, including Aurora B–dependent phosphorylation cycles.

Distribution and evidence: Evidence comes from immunofluorescence localization, co-immunoprecipitation, and mass spectrometry in several model organisms. However, the ubiquity and essentiality of kinetochorami remain debated; some studies report organism-specific or cell-cycle–dependent appearance, while others question whether observations reflect a stable subcomplex or transient interactions.

Terminology and status: The name kinetochorami is not universally adopted and is sometimes used as a provisional label for a set of interacting proteins rather than a defined complex. Ongoing research seeks to establish whether kinetochorami constitute a conserved, functional subassembly of the kinetochore across eukaryotes.