second PWWP domain found in nuclear receptor-binding SET domain-containing (NSD) proteins
The nuclear receptor binding SET domain (NSD) protein family consists of three HMTases, NSD1, NSD2/MMSET/WHSC1, and NSD3/WHSC1L1, that are critical in maintaining chromatin integrity. Reducing NSD activity through specific lysine-HMTase inhibitors appears promising in suppressing cancer growth. NSD proteins have specific mono- and dimethylase activities for H3K36, and they play nonredundant roles during development. NSD1 plays a role in several pathologies, including but not limited to Sotos and Weaver syndromes, acute myeloid leukemia, breast cancer, neuroblastoma, and glioblastoma formation. NSD2 is involved in cancer cell proliferation, survival, and tumor growth, by mediating constitutive NF-kappaB signaling via the cytokine autocrine loop. NSD3 is amplified in human breast cancer cell lines. Moreover, translocation resulting in NUP98 fusion to NSD3 leads to the development of acute myeloid leukemia. NSD proteins contain a catalytic suppressor of variegation, enhancer of zeste and trithorax (SET) domain, two proline-tryptophan-tryptophan-proline (PWWP) domains, five plant homeodomain (PHD) fingers, and an NSD-specific Cys-His rich domain (C5HCH). This model corresponds to the second PWWP domain. The family also includes Drosophila melanogaster maternal-effect sterile 4 (dMes4) that may act as a histone-lysine N-methyltransferase required for wing morphogenesis. The PWWP domain specifically recognizes DNA and histone methylated lysines.