KNL1 (kinetochore scaffold 1, aka CASC5) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that is encoded by the ''KNL1''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

in humans.

Function

KNL1 is part of the outer

kinetochore A kinetochore (, ) is a flared oblique-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers, which can be thought of as the ropes pulling chromosomes apart, attach during cell division to ...

. It is a part of KMN network of proteins together with

MIS12 Protein MIS12 homolog is a protein that in humans is encoded by the ''MIS12'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is t ...

, and

NDC80 Kinetochore protein NDC80 homolog is a protein that in humans is encoded by the ''NDC80'' gene. Function Ndc80 is one of the proteins of outer kinetochore. It forms a heterotetramer with proteins NUF2, SPC25, and SPC24. This protein complex ...

. KNL1 is involved in

microtubule Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nanometer, nm and have an inner diameter bet ...

attachment to chromosome centromeres and in the activation of the

spindle checkpoint The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during metaphase of mitosis or meiosis that preven ...

during mitosis. The ''CASC5'' gene is

upregulated In biochemistry, in the biological context of organisms' regulation of gene expression and production of gene products, downregulation is the process by which a cell decreases the production and quantities of its cellular components, such as RNA ...

in the areas of cell proliferation surrounding the ventricles during fetal brain development.

Interactions

CASC5 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...

with

BUB1 Mitotic checkpoint serine/threonine-protein kinase BUB1 also known as BUB1 (budding uninhibited by benzimidazoles 1) is an enzyme that in humans is encoded by the ''BUB1'' gene. Bub1 is a serine/threonine protein kinase first identified in genet ...

, BUBR1 and ZWINT-1.

Polymorphisms

Homozygous polymorphisms in the ''CASC5'' gene have been seen in patients with autosomal recessive primary

microcephaly Microcephaly (from Neo-Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it m ...

(MCPH). The mutation resulted in the skipping of exon 18

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, often th ...

, causing a frameshift and the production of a truncated protein. This truncation inhibits the binding ability of MIS12.

Function

Interactions

Polymorphisms

References

External links

Further reading