Search bioRxiv⌕ Search

Biology subjects

Koerner, M.

Publications and source records attributed to Koerner, M..

2 recordsLinked to original sources
bioRxiv2023

Insights into human outer kinetochore assembly and force transmission from a structure-function analysis of the KMN network

The biorientation of chromosomes during cell division is necessary for precise dispatching of a mother cells chromosomes into its two daughters. Kinetochores, large layered structures built on specialized chromosome loci named centromeres, promote biorientation by binding and sensing spindle microtubules. The kinetochore outer layer consists of a 10-subunit apparatus comprising Knl1C, Mis12C, and Ndc80C subcomplexes (KMN network). The KMN network is highly elongated and docks on kinetochores and microtubules using interfaces at its opposite extremes. Here, we combine cryo-EM reconstructions and AlphaFold2 predictions to generate a model of the KMN network that reveals all intra-KMN interfaces. We identify and functionally validate two interaction interfaces that link Mis12C to Ndc80C and Knl1C. Through targeted interference experiments and molecular dynamics simulations we demonstrate this mutual organization stabilizes the KMN network. Our work reports the first comprehensive structural and functional analysis of the microtubule binding machinery of kinetochores and elucidates a path of microtubule-generated force transmission

molecular biology↗
bioRxiv2018

A mutation-led search for novel functional domains in MeCP2

Most missense mutations causing Rett syndrome affect domains of MeCP2 that have been shown to either bind methylated DNA or interact with a transcriptional co-repressor complex. Several mutations, however, including the C-terminal truncations that account for ~10% of cases, fall outside these characterised domains. We studied the molecular consequences of four of these \"non-canonical\" mutations in cultured neurons and mice to see if they reveal additional essential domains without affecting known properties of MeCP2. The results show that the mutations partially or strongly deplete the protein and also in some cases interfere with co-repressor recruitment. These mutations therefore impact the activity of known functional domains and do not invoke new molecular causes of Rett syndrome. The finding that a stable C-terminal truncation does not compromise MeCP2 function raises the possibility that small molecules which stabilise these mutant proteins may be of therapeutic value.

molecular biology↗