Family With Sequence Similarity 3, Member B (FAM3B)

The authors predicted that FAM3B forms a 4-helix bundle, and 3-dimensional modeling indicated that 4 cysteines could form 2 disulfide bonds linking helices 1 and 4 and helices 2 and 3. The human and mouse FAM3B proteins share 78% amino acid identity. Northern blot analysis detected FAM3B expression at a high level in pancreas and at lower levels in small intestine and prostate. Immunohistochemical analysis of mouse tissues detected prominent Fam3b staining in the endocrine pancreas, specifically in the islets of Langerhans. Staining was also found in round spermatids within the seminiferous tubules, in the Purkinje cell layer of the cerebellum, and in nerve cell bodies of numerous brainstem nuclei. Transfected Chinese hamster ovary cells secreted Fam3b to the culture medium.