Inner centromere protein 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 in humans is encoded by the ''INCENP''

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 mammalian cells, two broad groups of

centromere The centromere links a pair of sister chromatids together during cell division. This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm (q) on the chromatids. During mitosis, spindle fibers ...

-interacting proteins have been described: constitutively binding

proteins and 'passenger' (or transiently interacting) proteins. The constitutive proteins include CENPA (centromere protein A),

CENPB Centromere protein B also known as major centromere autoantigen B is an autoantigen protein of the cell nucleus. In humans, centromere protein B is encoded by the CENPB gene. Function Centromere protein B is a highly conserved protein that ...

CENPC1 Centromere protein C 1 is a protein that in humans is encoded by the ''CENPC1'' gene. Centromere protein C 1 is a centromere autoantigen and a component of the inner kinetochore plate. The protein is required for maintaining proper kinetochore si ...

, and CENPD. The term 'passenger proteins' encompasses a broad collection of proteins that localize to the centromere during specific stages of the

cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA ( DNA replication) and some of its organelles, and sub ...

. These include CENPE; MCAK; KID; cytoplasmic dynein (e.g., DYNC1H1); CliPs (e.g. CLIP1); and CENPF/mitosin ( CENPF). The inner centromere proteins (INCENPs), the initial members of the passenger protein group, display a broad localization along chromosomes in the early stages of

mitosis In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maint ...

but gradually become concentrated at centromeres as the cell cycle progresses into mid-metaphase. During telophase, the proteins are located within the midbody in the intercellular bridge, where they are discarded after

cytokinesis Cytokinesis () is the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and me ...

. INCENP is a regulatory

in the

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

passenger complex. It is involved in regulation of the

catalytic Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycl ...

protein Aurora B. It performs this function in association with two other

s -

Survivin Survivin, also called baculoviral inhibitor of apoptosis repeat-containing 5 or BIRC5, is a protein that, in humans, is encoded by the ''BIRC5'' gene. Survivin is a member of the inhibitor of apoptosis (IAP) family. The survivin protein functions ...

and

Borealin Borealin is a protein that in humans is encoded by the ''CDCA8'' gene. Function CDCA8 is a component of a chromosomal passenger complex required for stability of the bipolar mitotic spindle. Interactions CDCA8 has been shown to interact wi ...

. These

proteins 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, respondi ...

form a tight three-helical bundle. The N-terminal

domain Domain may refer to: Mathematics *Domain of a function, the set of input values for which the (total) function is defined ** Domain of definition of a partial function **Natural domain of a partial function **Domain of holomorphy of a function *Do ...

of INCENP is the domain involved in formation of this three-helical bundle.

Interactions

INCENP has been shown to interact with H2AFZ,

and CDCA8. The ARK binding region has been found to be necessary and sufficient for binding to aurora-related

kinase In biochemistry, a kinase () is an enzyme that catalysis, catalyzes the transfer of phosphate groups from High-energy phosphate, high-energy, phosphate-donating molecules to specific Substrate (biochemistry), substrates. This process is known as ...

. This interaction has been implicated in the coordination of

chromosome segregation Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segrega ...

with

cell division Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there ar ...

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to consti ...

Interactions

References

Further reading