CENP-A is a centromere-specific variant of histone H3 that is required for 
accurate chromosome segregation. The fission yeast Schizosaccharomyces pombe and 
mammalian Mis16 and Mis18 form a complex essential for CENP-A recruitment to 
centromeres. It is unclear, however, how the Mis16-Mis18 complex achieves this 
function. Here, we identified, by mass spectrometry, novel fission yeast 
centromere proteins Mis19 and Mis20 that directly interact with Mis16 and Mis18. 
Like Mis18, Mis19 and Mis20 are localized at the centromeres during interphase, 
but not in mitosis. Inactivation of Mis19 in a newly isolated 
temperature-sensitive mutant resulted in CENP-A delocalization and massive 
chromosome missegregation, whereas Mis20 was dispensable for proper chromosome 
segregation. Mis19 might be a bridge component for Mis16 and Mis18. We isolated 
extragenic suppressor mutants for temperature-sensitive mis18 and mis19 mutants 
and used whole-genome sequencing to determine the mutated sites. We identified 
two groups of loss-of-function suppressor mutations in non-sense-mediated mRNA 
decay factors (upf2 and ebs1), and in SWI/SNF chromatin-remodeling components 
(snf5, snf22 and sol1). Our results suggest that the Mis16-Mis18-Mis19-Mis20 
CENP-A-recruiting complex, which is functional in the G1-S phase, may be 
counteracted by the SWI/SNF chromatin-remodeling complex and non-sense-mediated 
mRNA decay, which may prevent CENP-A deposition at the centromere.