Cloning And Characterization Of Two Novel CDNAs Predominantly Expressed In Human Nervous System: HNTM And HMP19

Human nervous system plays a crucial role in the life of individuals, from embryonic development to growth, maturation and aging. The cloning and study of genes related to the function of nervous system have become not only the research hot spot of modern neuroscience, but also the keystone of molecular genetics and developmental biology. Many expressed sequences in nervous system have been successfully located on human chromosomes, which provide a solid base for the structural and functional study of genes expressed in nervous system.In order to isolate and clone novel genes related to the function of the human nervous system, we analyzed the protein families which play an important role in the nervous function. Some ESTs were chosen as the probes for cDNA library screening and several full length cDNA clones were isolated from the human fetal brain cDNA library. In this thesis, the cloning and characterization of two full-length cDNAs were reported.Proteins of the immunoglobulin superfamily (IgSF) are involved in a variety of specific cell-cell interactions in the development of nervous system. We isolated a full-length cDNA clone from a human brain cDNA library. The cDNA contains a 1032 bp open reading frame encoding a protein of 344 amino acids which has three C2-like immunoglobulin domains. The N-terminal 31 amino acids are quite hydrophobic and likely to correspond to a signal peptide, with a potential cleavage site at Arg 32. The C-terminus also contains a hydrophobic sequence of 18 amino acids, consistent with a GPI-anchor attachment signal. Based on the analysis of the attachment signals in other proteins, the most favorable site for GPI-anchor attachment is Gly 322. The results of alignment indicated that the clone obtained are 93% identical to rat neurotrimin overall in peptide sequence and 87% identical in...