Retrotransposon Gag like 3 is a protein that in humans is encoded by the RTL3 gene.[1]
This gene is a member of a family of gag-related retrotransposon genes. These genes appear to have lost the ability to retrotranspose; however, their open reading frames have remained intact, which may indicate that these genes have acquired new functions in the cell. Retrotransposon gag-like-3 (RTL3/ZCCHC5/MART3) is one of eleven Sushi-like neogenes identified in the human genome7 RTL3 encodes a 53 kDa protein with a nucleic acid-binding domain (CX2CX4HX4C), gag-like region within the open reading frame and an ssDNA/RNA-binding homeobox-associated leucine zipper motif.[2] It has been reported that RTL3 and SOX-9 co-regulate the expression of COL2A1 in chondrocytes.