KNSTRN

Essential component of the mitotic spindle required for faithful chromosome segregation and progression into anaphase (PubMed:19667759). Promotes the metaphase-to-anaphase transition and is required for chromosome alignment, normal timing of sister chromatid segregation, and maintenance of spindle pole architecture (PubMed:19667759, PubMed:22110139). The astrin (SPAG5)-kinastrin (SKAP) complex promotes stable microtubule-kinetochore attachments (PubMed:21402792). Required for kinetochore oscillations and dynamics of microtubule plus-ends during live cell mitosis, possibly by forming a link between spindle microtubule plus-ends and mitotic chromosomes to achieve faithful cell division (PubMed:23035123). May be involved in UV-induced apoptosis via its interaction with PRPF19; however, these results need additional evidences (PubMed:24718257).

Full Name

kinetochore-localized astrin/SPAG5 binding

Function

Essential component of the mitotic spindle required for faithful chromosome segregation and progression into anaphase (PubMed:19667759).
Promotes the metaphase-to-anaphase transition and is required for chromosome alignment, normal timing of sister chromatid segregation, and maintenance of spindle pole architecture (PubMed:19667759, PubMed:22110139).
The astrin (SPAG5)-kinastrin (SKAP) complex promotes stable microtubule-kinetochore attachments (PubMed:21402792).
Required for kinetochore oscillations and dynamics of microtubule plus-ends during live cell mitosis, possibly by forming a link between spindle microtubule plus-ends and mitotic chromosomes to achieve faithful cell division (PubMed:23035123).
May be involved in UV-induced apoptosis via its interaction with PRPF19; however, these results need additional evidences (PubMed:24718257).

Biological Process

Cell divisionIEA:UniProtKB-KW
Cell migrationManual Assertion Based On ExperimentIMP:ARUK-UCL
Cellular response to epidermal growth factor stimulusManual Assertion Based On ExperimentIMP:ARUK-UCL
Chromosome segregationManual Assertion Based On ExperimentIMP:UniProtKB
Microtubule cytoskeleton organizationManual Assertion Based On ExperimentIMP:ARUK-UCL
Mitotic sister chromatid segregationManual Assertion Based On ExperimentIMP:UniProtKB
Regulation of attachment of spindle microtubules to kinetochoreManual Assertion Based On ExperimentIMP:UniProtKB
Spindle organizationManual Assertion Based On ExperimentIMP:UniProtKB

Cellular Location

Nucleus
Chromosome, centromere, kinetochore
Cytoplasm, cytoskeleton, spindle pole
Cytoplasm, cytoskeleton, microtubule organizing center
Colocalizes with microtubules around centrosomes in prophase and with the mitotic spindle at prometaphase and metaphase. From late prometaphase to anaphase, is highly concentrated on kinetochores. Located at the kinetochore-microtubule interface. The astrin (SPAG5)-kinastrin (SKAP) complex localizes to the microtubule plus ends (PubMed:23035123).

Involvement in disease

Roifman-Chitayat syndrome (ROCHIS):
An autosomal recessive digenic disorder characterized by global developmental delay, variable neurologic features such as seizures and ataxia, optic atrophy, dysmorphic facial features, distal skeletal anomalies, and recurrent invasive infections due to combined immunodeficiency.
Cutaneous squamous cell carcinomas (SCC): A malignancy of the skin. The hallmark of cutaneous SCC is malignant transformation of normal epidermal keratinocytes. Disease susceptibility is associated with variants affecting the gene represented in this entry. Variant Phe-24 appears specific for UV-associated malignancies (PubMed:25194279).