Molecular cloning and expression of a novel peptide (LN1) gene: reduced expression in the renal cortex of lupus nephritis in MRL/lpr mouse.

A gene has been identified by mRNA differential display whose expression is reduced in the renal cortex of MRL/lpr mouse. The nucleotide sequence of the cDNA contains an open reading frame that encodes a protein of 338 amino acids (termed LN1). In situ hybridization showed that LN1 mRNA is present in glomeruli, and a 39 kDa protein was detected in the kidney by immunoblot. A human LN1 cDNA was also isolated, the deduced amino acid sequence of which is 78% identical to that of mouse LN1. Although the function of LN1 remains to be elucidated, its reduced expression may contribute to the pathogenesis of lupus nephritis.