Family With Sequence Similarity 65, Member B (FAM65B)

The 536-amino acid protein has a calculated molecular mass of 59.8 kD and contains a transmembrane region, 2 glycosaminoglycan attachment sites, 4 N-linked glycosylation sites, and numerous potential phosphorylation sites. Northern blot analysis of spontaneously differentiating human cytotrophoblasts detected 2.8-, 3.5-, and 4.8-kb transcripts at 2 hours with increased expression over time of differentiation. PLA48 was not expressed in undifferentiated myeloid leukemia cells, but expression increased between 24 and 72 hours following DMSO-induced granulocytic lineage differentiation. PL48 acted as an early response gene during spontaneous cytotrophoblast differentiation but was induced later in the DMSO-induced granulocytic differentiation pathway.