title: Conformational determinants of the intracellular localization of midkine.
abstract: Midkine (MK) is a multifunctional growth factor and has been discovered to play important roles in carcinogenesis. MK has been reported to localize to the nucleus and nucleolus, however, the data are not consistent and the signals responsible for the localization are unknown. Here we reported that human MK exclusively localized to the nucleus and nucleolus in HepG2 cells by using GFP as a tracking molecule. In order to identify the motifs required for the nuclear localization and nucleolar accumulation, point- and deletion-mutations were introduced and the corresponding subcellular localizations were analyzed. Data revealed that (i) K79R81, K86K87, and the C-terminal tail of MK constitute the nuclear localization determinant of MK, and (ii) the C-terminal tail is the key element controlling MK nucleolar accumulation though the N-terminal tail, K79R81, and K86K87 also contribute to this process. Taken together, our results provide the first documentation about the determinants required for MK nuclear and nucleolar localization.
authors.affiliation: Huzhou Central Hospital, Huzhou 313000 [corrected] China.
authors.forename: Licheng
authors.initials: L
authors.lastname: Dai
authors.forename: Lichen
authors.initials: L
authors.lastname: Dai
authors.forename: Diyong
authors.initials: D
authors.lastname: Xu
authors.forename: Xing
authors.initials: X
authors.lastname: Yao
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Lu
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D016207:Cytokines / Q000737:chemistry / Q000378:metabolism*; D017931:DNA Primers; D006801:Humans; D000078792:Midkine; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D016207:Cytokines; D017931:DNA Primers; D000078792:Midkine