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Members of the MAPK superfamily are known as key regulators of ciliogenesis. Long flagellar (LF) 4, a MAPK-related kinase in Chlamydomonas, is the first kinase that was implicated in ciliary assembly and length. However, little is known about its cellular properties, regulation, and molecular functions. LF4 is localized both in the flagella and cell body with enrichment at the 2 basal bodies, shown by super-resolution microscopy. LF4 is constitutively phosphorylated at T159 at the kinase activation loop and remains at the basal bodies during flagellar assembly. Gene mutations that affect the kinase activity or T159 phosphorylation alter the localization of LF4 at the basal bodies, and the mutants fail to rescue lf4-3, a null mutant. LF4 does not affect the velocities of intraflagellar transport (IFT). However, LF4 null mutation induces accumulation of IFT proteins in the flagellum and reduces the phosphorylation of the kinesin-II subunit FLA8/KIF3B, indicating that LF4 negatively regulates IFT entry. Furthermore, LF2, a cell cycle-related kinase, and LF3, a novel protein, are required for LF4 phosphorylation. Our study demonstrates that LF4 is likely a constitutively active kinase that is regulated by LF2 and regulates IFT entry at the basal bodies to control flagellar assembly and length. [ABSTRACT FROM AUTHOR]

Purpose: CD24 is overexpressed in hepatocellular carcinoma (HCC) tumor tissues and in the highly metastatic HCC cell lines. However, plasma CD24 level in HCC patients and the correlation of plasma CD24 level with clinicopathological factors and prognosis of HCC patients still remain unclear. Materials and Methods: Enzyme-linked immunosorbent assay was used to detect plasma CD24 level in 86 HCC patients, 35 healthy subjects, 26 patients with liver cirrhosis and 23 patients with chronic hepatitis. The relationship between plasma CD24 level with clinicopathological characteristics in HCC patients was assessed using the Mann-Whitney U test. Patient survival between groups was evaluated by the Kaplan-Meier method and the log-rank test, prognostic factors being analyzed by the Cox regression model. Results: Our present study demonstrated that plasma CD24 level in HCC patients was significantly higher than that in the controls. CD24 was significantly associated with tumor differentiation, but was not correlated with other clinicopathologic parameters including gender, age, tumor size, tumor number, capsulation status, HBsAg status, tumor node metastasis stage, ALT, AFP, and GGT level. CD24 might be a prognostic predictor for overall survival and recurrence-free survival. Conclusions: Plasma CD24 level was significantly higher in HCC patients than that in the controls. Plasma CD24 level was associated with tumor differentiation. The HCC patients with high plasma CD24 level had unfavorable prognosis. CD24 might be a prognostic biomarker for HCC in the future. [ABSTRACT FROM AUTHOR]