May act as a co-chaperone for HSP83. Forms a complex with Hsp83 and Hsp70aa (PubMed:11493638). Interacts with DNApol-alpha180; the interaction inhibits the activity of the DNA polymerase and occurs only in proliferating cells but not in quiescent cells (PubMed:11493638). In embryos prior to cellularisation, found in the nucleus and cytoplasm but after cellularisation seen predominantly in the nucleus. More abundant in young embryos, pupae and females and a lower level expression seen in late embryos, larvae and males. Belongs to the TTC4 family.