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 residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

that is encoded by the ''KNL1''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

in humans.

Function

KNL1 is part of the outer

kinetochore A kinetochore (, ) is a disc-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere ...

. 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. Interactions MIS12 has been shown to interact with NSL1 Kinetochore-associated protein NSL1 homolog is a protein that in humans is encoded by the ''NSL1'' g ...

, 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 ha ...

. KNL1 is involved in microtubule 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 mitosis or meiosis that prevents the separa ...

during mitosis. The ''CASC5'' gene is

upregulated In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary pr ...

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 using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizat ...

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 geneti ...

, BUBR1 and ZWINT-1.

Polymorphisms

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

microcephaly Microcephaly (from New 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 ...

(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, the fir ...

, causing a

frameshift Ribosomal frameshifting, also known as translational frameshifting or translational recoding, is a biological phenomenon that occurs during translation that results in the production of multiple, unique proteins from a single mRNA. The process c ...

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

Function

Interactions

Polymorphisms

References

External links

Further reading