Human kinesin superfamily member 4 is dominantly localized in the nuclear matrix and is associated with chromosomes during mitosis

Abstract

In a previous study, we identified the human counterpart of murine kinesin superfamily member 4 (KIF4), a microtubule-based motor protein [Oh, Hahn, Torrey, Shin, Choi, Lee, Morse and Kim (2000) Biochim. Biophys. Acta 1493, 219–224]. As an initial step to understand the function(s) of human KIF4, its subcellular localization in HeLa cells was examined by using immunocytochemical and subcellular fractionation methods, and it was found that most KIF4 is localized in the nucleus. Since murine KIF4 is known to transport cytoplasmic vesicles, dominant nuclear localization of the human counterpart was somewhat surprising. Subsequent subnuclear fractionation revealed predominant association of KIF4 with the nuclear matrix. These results clearly indicate that human KIF4 is, at least, a nuclear protein. In further confirmation of this conclusion, the hexapeptide PKLRRR (amino acids 773–778) in the molecule was found to function as a nuclear localization signal. During the mitotic phase of the cell cycle, human KIF4 was associated with the chromosomes, suggesting that human KIF4 might be a microtubule-based mitotic motor, with DNA as its cargo.

Overexpression of chromokinesin KIF4 inhibits proliferation of human gastric carcinoma cells both in vitro and in vivo

“…1b-h). Immunohistochemical analysis clearly showed KIF4 localized in cytoplasm and nucleus in gastric tissue cells, which is consistent with previous reports in other human tissues or in vitro-cultured cells [21,22] (Fig. 1e, f).…”

Interplay of Microtubule Dynamics and Sliding during Bipolar Spindle Formation in Mammalian Cells

“…1G). Likewise, depletions of either a chromokinesin (Kif4) [10], a pole focusing motor (HSET) [11], or microtubule-associated proteins TOG [12] and EB1 [13] did not significantly change the monopolarity index, ruling out those proteins in maintaining spindle bipolarity in the absence of Eg5 activity as well (Fig. 1G).…”

Identification and phylogenetic analysis of Dictyostelium discoideum kinesin proteins

“…Kif4 from mammals has been shown to function in the anterograde transport of certain organelles in juvenile neurons and other cells [69]. Furthermore, it colocalized at the mitotic spindle during mitosis, where it is associated with chromosomes [70]. Dd Kif8 was found to be constitutively expressed [30].…”