KNL1

KNL1 (kinetochore scaffold 1, aka CASC5) is a protein that is encoded by the "KNL1" gene in humans.
Function.
KNL1 is part of the outer kinetochore. It is a part of KMN network of proteins together with MIS12, and NDC80.
KNL1 is involved in microtubule attachment to chromosome centromeres and in the activation of the spindle checkpoint during mitosis. The "CASC5" gene is upregulated in the areas of cell proliferation surrounding the ventricles during fetal brain development.
Interactions.
CASC5 has been shown to interact with MIS12, BUB1, BUBR1 and ZWINT-1.
Polymorphisms.
Homozygous polymorphisms in the "CASC5" gene have been seen in patients with autosomal recessive primary microcephaly (MCPH). The mutation resulted in the skipping of exon 18 transcription, causing a frameshift and the production of a truncated protein. This truncation inhibits the binding ability of MIS12.