Expression and cellular localization of the protein encoded by the 1C7 gene: a recently described component of the MHC

The major histocompatibility complex (MHC) is located on human Chromosome 6 and includes clusters of class I, class II, and class III genes. Centromer ic to the class I region is a cluster of genes designated as MHC class IV e ncoding genes involved in immunity and inflammation, including the 1C7 gene . The human 1C7 gene has several alternatively spliced forms and potentiall y codes for proteins with at least three unique carboxy termini. 1C7 mRNA i n human (h1C7) is present in spleen, tonsil, B and NK cell lines, and with a different splicing pattern in liver. The 1C7 RNA and protein are present at highest levels in the germinal center of the lymphoid follicles in tonsi l. The protein is expressed in NKL cells, tonsil, and unexpectedly in brain . In contrast, the mouse 1C7 gene is transcribed in liver but is predicted to be a pseudogene. However, the 1C7 homologue expressed in rat is predicte d to have long stretches of amino acids essentially identical to the human protein.