HUMAN NEURONAL PENTRAXIN-II (NPTX2) - CONSERVATION, GENOMIC STRUCTURE, AND CHROMOSOMAL LOCALIZATION

We have previously identified a novel rat neuronal member of the pentr axin family (neuronal pentraxin) that may mediate the uptake of synapt ic material and the presynaptic snake venom toxin, taipoxin. Here we r eport human cDNA and genomic sequences of a second neuronal pentraxin. This pentraxin, which we propose to name neuronal pentraxin LI (NPII; gene symbol NPTX2), shows 54% amino acid identity to rat neuronal pen traxin (NPI) with 69% identity over the carboxyl-terminal half of NPI and is 88% identical to a newly identified sperm acrosomal pentraxin p 50/apexin. Northern blot analysis reveals that NPII message is present in brain, testis, pancreas, liver, heart, and skeletal muscle, so, un like NPI, NPII is not exclusively localized to neurons. Like NPI, NPII has potential N-linked glycosylation sites. The human NPII gene is 11 kb in length, contains four introns, and is localized to chromosome 7 q21.3-q22.1. These data demonstrate the existence of a family of pentr axin proteins that are expressed in the brain and other tissues and th at may play important roles in the uptake of extracellular material. ( C) 1995 Academic Press, Inc.