The perinucleolar compartment (PNC) is a subnuclear structure associated with, but structurally distinct from, the nucleolus. The PNC contains large amounts of the heterogeneous nuclear ribonucleoprotein complex (hnRNP) called hnRNP 1 (PTB). Many RNA binding proteins as well as RNA polymerase III transcripts are highly enriched in this compartment. PTB and pol III transcripts are required for the integrity of the PNC. [ http://www.ncbi.nlm.nih.gov/pubmed/21385875 GOC:vw http://en.wikipedia.org/wiki/Perinucleolar_compartment ]