The Abnormal Spindle-like,Microcephaly-associated (ASPM) Gene Encodes a Centrosomal Protein

Homozygous mutations in the abnormal spindle-like, microcephaly-associatedASPM gene are the leading cause of autosomal recessive primary microcephaly. ASPM isthe putative human ortholog of the Drosophila melanogaster abnormal spindles gene(asp), which is essential for mitotic spindle function. Here, we report thatdownregulation of endogenous ASPM by siRNA decreases protein levels of endogenousBRCA1. ASPM localizes to the centrosome in interphase and to the spindle poles fromprophase through telophase. These findings indicate that ASPM may be involved inmitotic spindle function, possibly, through regulation of BRCA1.