Recent origin of a hominoid specific splice form of neuropsin
A research team headed by Dr. Su Bing, a researcher at the CAS Kunming Institute of Zoology, has made novel progress in their studies into a hominoid specific splice form of neuropsin. Their discovery has been published online on July 28, 2004 by the UK-based journal Molecular Biology and Evolution.
Neuropsin is a secreted-type serine protease involved in learning and memory. The Type-II splice form of neuropsin is abundantly expressed in the human brain, but not in the mouse brain. Su and colleagues sequenced the Type -II spliced region of neuropsin gene in humans and representative nonhuman primate species. A comparative sequence analysis by the group showed that only the hominoid species (humans and apes) have the intact open reading frame of the Type-II splice form, indicating that the Type -II neuropsin originated recently in the primate lineage about 18 million years ago. An expression analysis using RT-PCR detected abundant expression of the Type -II form in the frontal lobe of the adult human brain, but no expression was detected in the brains of lesser apes and Old World monkeys, indicating that the Type-II form of neuropsin only became functional in recent time and it might contribute to the progressive change of cognitive abilities during primate evolution.