Kinetochore scaffold 1 (KNL1)

Kinetochore scaffold 1 (KNL1) is a large, evolutionarily conserved scaffolding protein forming part of the outer kinetochore complex, essential for correct chromosome segregation during mitosis and meiosis. Its primary function is to organize the recruitment and assembly of spindle assembly checkpoint (SAC) signalling proteins—including Bub1, BubR1, and Bub3—at the kinetochore. KNL1 also mediates microtubule attachment to kinetochores, working as part of the KMN (KNL1-Mis12-Ndc80) network, which connects the centromeric chromatin to spindle microtubules—a key requirement for biorientation and genetic stability during cell division. Mutations in KNL1 can cause autosomal recessive primary microcephaly, and the gene is implicated as a fusion partner in certain leukemias. It is widely expressed in both fetal and adult tissues, especially in testes and various tumors. As no drugs directly target KNL1 in clinical practice, it is primarily studied as a cancer biomarker and as a potential point of intervention for anti-mitotic therapies. Suppression or mutation of KNL1 disrupts cell division, which can have therapeutic implications for cancer but also carries significant safety concerns due to its necessity for normal cell cycle progression.

Other names

CASC5KIAA1570AF15q14BlinkinCT29D40hKNL-1hSpc105PPP1R55Spc7ALL1-fused gene from chromosome 15q14 proteinBub-linking kinetochore proteinCancer susceptibility candidate gene 5 proteinCancer/testis antigen 29Kinetochore-null protein 1Protein D40/AF15q14Microcephaly, primary autosomal recessive 4 (MCPH4)Knl1, CASC5, CT29, D40, AF15Q14, MCPH4, PPP1R55, Spc7, hKNL-1, hSpc105, outer kinetochore KNL1 complex subunit KNL1

Research suggests inhibition would disrupt chromosome segregation, potentially halting mitosis or inducing cell death in proliferating cells such as tumors. Mechanistic focus is on interfering with SAC protein recruitment and kinetochore assembly.