Protein mab-21-like 4 (MAB21L4)

Protein mab-21-like 4 (MAB21L4) is a member of the MAB21-like family, structurally related to the nucleotidyltransferase (NTase) superfamily[1][2]. It is predominantly cytosolic and interacts with regulatory proteins such as c-Ski and Smad3, modulating the transforming growth factor beta (TGF-β) signaling pathway, which is essential for epidermal differentiation and gene expression in keratinocytes[2][3]. MAB21L4 acts to amplify TGF-β–dependent gene expression, at least in part by counteracting c-Ski's transcriptional repression, thereby facilitating the expression of target genes critical for skin barrier formation such as involucrin[2][3]. It serves as a tumor suppressor in several epithelial cancers including cutaneous, cervical, and head and neck squamous cell carcinomas—where its reduced expression associates with increased tumorigenesis and poorer prognosis[5]. MAB21L4's full enzymatic activity remains to be directly demonstrated, though sequence and structural similarity with characterized NTase family members suggest possible nucleotidyltransferase function[1][2]. Its precise physiological and pathological roles are still being explored, but current evidence supports its relevance in epidermal biology and cancer biology[2][3][5].

Other names

MAB21L4C2orf54FLJ22671uncharacterized protein C2orf54protein mab-21-like 4