small kinetochore-associated protein; SKAP; kinetochore-localized astrin-binding protein; kinastrin; kinetochore-localized astrin/SPAG5-binding protein; TRAF4-associated factor 1 (KNSTRN, C15orf23, SKAP, TRAF4AF1, HSD11)

Function: - essential component of the mitotic spindle - promotes the metaphase-to-anaphase transition - required for chromosome alignment, normal timing of sister chromatid segregation, & maintenance of spindle pole architecture - component of an astrin (SPAG5)-kinastrin (SKAP) complex - promotes stable microtubule-kinetochore attachments - interacts with SPAG5 - directly binds to microtubules, although at relatively low affinity - interacts with CENPE interaction greatly favors microtubule-binding Compartment: - nucleus. chromosome, centromere, kinetochore - cytoplasm, cytoskeleton, spindle pole - colocalizes with microtubules around centrosomes in prophase & with the mitotic spindle at prometaphase & metaphase - from late prometaphase to anaphase, is highly concentrated on kinetochores Alternative splicing: named isoforms=3 Expression: - degraded at the end of mitosis - down-regulated upon exposure to nitric oxide

General

nuclear protein phosphoprotein

Properties

SIZE: entity length = 316 aa MW = 35 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: Ser phosphorylation site {S128} SPAG5 interaction {159-316} MOTIF: coiled coil {166-216} coiled coil {248-316}

Database Correlations

OMIM 614718 UniProt Q9Y448 Entrez Gene 90417 Kegg hsa:90417

References

UniProt :accession Q9Y448