Islet Cell Autoantigen 1 Like Protein (ICA1L)

Ica69 related protein, the causative gene product for juvenile recessive amyotrophic lateral sclerosis (ALS2), is a guanine-nucleotide exchange factor for the small GTPase Rab5. Ectopically expressed ALS2 protein localizes with Rab5 and early endosome antigen-1 (EEA1) onto early endosomal compartments and stimulates the enlargement of endosomes in cultured cortical neurons. Islet cell autoantigen 1, 69kDa, also known as ICA1 is a protein with an arfaptin homology domain that is found both in the cytosol and as membrane-bound form on the Golgi complex and immature secretory granules. This protein is believed to be an autoantigen in insulin-dependent diabetes mellitus and primary Sjogren's syndrome. Alternatively spliced variants which encode different protein isoforms have been described; however, not all variants have been fully characterized.