Abstract: During the process of open mitosis in higher eukaryotic cells, the nuclear envelope (NE) is disassembled and reassembled with highly organized and periodical dynamic morphological changes. Recent studies demonstrated that LEM-domain protein family mediates interactions among inner nuclear membrane, nuclear lamina protein and chromatin by interacting with barrier-to-autointegration-factor (BAF). The structure and function of the ternary complex formed by LEM-domain protein, nuclear lamina protein and BAF are dependent on each other. Moreover, the network formation based on this structure and function is critical for the development of basic biological processes of nuclear, and it plays important roles in chromatin separation in late metaphase and anaphase, NE reassembly after mitosis, morphological maintenance of nuclear and NE in interphase, regulation of DNA replication and DNA damage repair, regulation of gene expression and signaling pathway, and infection of retrovirus. Mutations in genes encoding LEM family proteins have important impacts on development and progression of laminopathic diseases and tumorigenesis. This review provides a detailed summary of structural and functional studies of the LEM family proteins.

Key words: LEM-domain protein, lamina, BAF, mitosis, NE disassembly and reassembly, laminopathies, tumorigenesis