Abnormal centrosomal structures similar to those occurring in human cancers are induced in fission yeast by overexpression of the pericentrin homolog Pcp1p. Analysis of abnormal Pcp1p-containing structures with quantitative mass spectrometry and isotope-coded affinity tags identified a coiled-coil, structural maintenance of chromosomes (SMC) domain protein. This protein, termed Ccq1p (coiled-coil protein quantitatively enriched), localizes with Taz1p to telomeres in normal vegetative cells. Fluorescence resonance energy transfer (FRET) measurements indicate that Ccq1p also interacts with centrosomal Pcp1p in mating pheromone-stimulated cells containing centrosomally clustered telomeres. We provide evidence that the Ccq1p-Pcp1p interaction, while essential for meiosis, is deleterious when forced to occur during vegetative growth. Cells lacking one ccq1 allele exhibit a loss-of-function phenotype including abnormally long cell length, chromosome segregation failure, telomeric shortening, and defective telomeric clustering during meiotic prophase. Our data indicate a mechanism underlying meiotic chromosomal bouquet formation and suggest a recruitment model for supernumerary centrosome toxicity.