ninein (hNinein, glycogen synthase kinase 3 beta-interacting protein, GSK3B-interacting protein, NIN, KIAA1565)

Function

• centrosomal protein required in positioning & anchorage of microtubule minus-end in epithelial cells
• centrosome maturation factor (putative)
• role in microtubule nucleation (elongation)
• overexpression does not perturb nucleation or elongation of microtubules but suppresses release of microtubules
• interacts with C14ORF166,, may prevent its phosphorylation by GSK3-beta
• interacts with GSK3B (GSK3-beta) via its C-terminus
• phosphorylated by Aurora A & PKA kinases but not CK2 or Aurora B

Structure

• homooligomer
• contains 5 EF-hand domains
• coiled coil region from Asn-1611 to Pro-1693 is necessary & sufficient for targeting to centrosome

Compartment

• centrosome
• component of core centrosome
• arranged in a tubular conformation with an open & a closed end within centrosome.
• in mother centrosome, localizes at both ends of the centrosome tube
• in the daughter centrosome, present only at the closed end
• requires PCM1 for centrosome localization

Alternative splicing

named isoforms=8

Expression

• ubiquitous
• highly expressed in heart & skeletal muscle
• isoform 1 is more expressed than isoform 5

Pathology

• antibodies against ninein are present in sera from patients with autoimmune diseases that develop autoantibodies against centrosomal proteins

More general terms

• cytoskeletal protein
• Ca+2 binding protein

Database

• OMIM: https://mirror.omim.org/entry/608684
• UniProt: http://www.uniprot.org/uniprot/Q8N4C6.html