CPAP (gene)
Centrosomal P4.1-associated protein is a protein that in humans is encoded by the CPAP gene (previously CENPJ). It has also been known as Centromere protein J (CENP-J). During cell division, this protein plays a structural role in the maintenance of centrosome integrity and normal spindle morphology, and it is involved in microtubule disassembly at the centrosome. This protein can function as a transcriptional coactivator in the Stat5 signaling pathway and also as a coactivator of NF-kappaB-mediated transcription, likely via its interaction with the coactivator p300/CREB-binding protein.
The Drosophila ortholog, sas-4, has been shown to be a scaffold for a cytoplasmic complex of Cnn, Asl, CP-190, tubulin and D-PLP (similar to the human proteins PCNT and AKAP9). These complexes are then anchored at the centriole to begin formation of the centrosome.
Clinical significance
Mutations in CENPJ are associated with Seckel syndrome type 4 and primary autosomal recessive microcephaly, a disorder characterized by severely reduced brain size and intellectual disability. Interestingly, CENPJ interacts with other microcephaly aossciated proteins such as WDR62 and both coordinate a regulatory function neocortical development and brain growth.