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

More general terms

• nuclear protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=90417
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:90417
• OMIM: https://mirror.omim.org/entry/614718
• UniProt: http://www.uniprot.org/uniprot/Q9Y448.html