Cloning and expression analysis of human reticulon 4c cDNA

RTNs (reticulons) is a gene family related to the growth and differentiation of neuroendocrine cell. This family is composed of several members such as RTN1, RTN2ar\d RTN3. RTN1 and RTN2 have been proved to have 3 transcripts with different length. Because the RTN1c cDNA was involved in the sologenesis of small cell lung carcinoma (SCLC), it was selected as a bioinformatic probe to clone novel members of RTN family with the electric hybridization assistant new-gene cloning method (EHAC). A 1677-bp cDNA was identified from human brain cDNA library. The cDNA contains an intact open reading frame (ORF) which encodes a protein of 199 amino acids. This deduced protein is highly homologous to RTN1c, RTN2c and RTN3 with identities of 64.4%, 45.8% and 50.0% respectively. This new gene was named RTN4c (GenBank accession number: AF087901). Northern hybridization showed that the full length of RTN4c transcript is about 1.8 kb. It is hardly expressed in heart, placenta, lung, spleen, thymus, testis, ovary, small in