Protein maelstrom homolog (MAEL)

Protein maelstrom homolog (MAEL) is an **RNA-binding protein** essential for spermatogenesis, functioning predominantly to repress and silence transposable elements via the piRNA pathway in germline cells[1][2][5][6]. MAEL is structurally characterized by an **amino-terminal High Mobility Group (HMG) box** and a **carboxy-terminal MAEL domain**, and while the MAEL domain shares homology with nucleases, it is catalytically inactive in metazoans and instead evolved to bind RNA[1][3]. MAEL localizes in the nuage of germ cells, mediating post-transcriptional silencing, and interacts with chromatin-remodeling and small-RNA pathway factors[2]. Uniquely, MAEL is classified as a **cancer/testis antigen** (CT antigen): it is almost exclusively expressed in germ cells under physiological conditions but becomes aberrantly expressed in a variety of cancers[2][4][6]. In tumors, this functionally links MAEL to cellular immortality, stemness, and tumor progression; its knockdown impairs cancer cell survival and induces DNA damage and apoptosis[6]. Elevated MAEL expression has been suggested as a marker for early-stage tumor detection, notably in gastric cancer with or without Helicobacter pylori infection[4]. No drugs targeting MAEL have been described, though its apparent requirement in cancers and restricted normal expression make it a potential biomarker and investigational target, rather than a confirmed therapeutic target.

Other names

FLJ14904CT128SPATA35cancer/testis antigen 128spermatogenesis associated 35testicular tissue protein Li 116