Involved in nucleolar processing of pre-18S ribosomal RNA. Required for optimal pre-ribosomal RNA transcription by RNA polymerase I together with a subset of U3 proteins required for transcription (t-UTPs). Involved in ribosome biosynthesis (By similarity). Component of the ribosomal small subunit (SSU) processome. Belongs to the HEATR1/UTP10 family.