Chromosomal protein which is recruited to mitotic chromosomes by hcp-3 (CENP-A) and hcp-4 (CENP-C) (PubMed:12080088, PubMed:15767665). Involved in chromosome segregation during mitosis, playing a role in chromosome condensation and in maintaining chromosome morphology, rigidity and orientation during mitosis (PubMed:12080088, PubMed:15767665). Component of the condensin-2 complex. Localizes to the centromere during mitosis (PubMed:12080088). Co-localizes with hcp-3 (CENP-A) at prophase, metaphase, and anaphase chromosomes (PubMed:12080088, PubMed:15767665). Mitotic chromosome localization is dependent on hcp-3 (CENP-A) and hcp-4 (CENP-C) (PubMed:12080088, PubMed:15767665). Localizes along two parallel lines on individual prophase chromosomes (PubMed:12080088). At metaphase, localizes at the poleward faces of the metaphase plate (PubMed:12080088). During anaphase, localizes with the separating groups of sister chromatids (PubMed:12080088). RNAi-mediated knockdown results in temperature sensitive embryonic lethality with chromosomes displaying segregation defects with increased anaphase bridges and chromosome lagging.