Identification of determinants that mediate binding between Tembusu virus and the cellular receptor heat shock protein A9

Heat shock protein A9 (HSPA9), a member of the heat shock protein family, is a putative receptor for Tembusu virus (TMUV). By using Western blot and co-immunoprecipitation assays, E protein domains I and II were identified as the functional domains that facilitate HSPA9 binding. Twenty-five overlapping peptides covering domain I and domain II sequences were synthesized and analyzed by using an HSPA9 binding assay. Two peptides showed the capability of binding to HSPA9. Dot blot assay of truncated peptides indicated that amino acid residues 19 to 22 and 245 to 252 of E protein constitute the minimal motifs required for TMUV binding to HSPA9. Importantly, peptides harboring those two minimal motifs could effectively inhibit TMUV infection. Our results provide insight into TMUV-receptor interaction, thereby creating opportunities for elucidating the mechanism of TMUV entry.

Expression and clinical significance of HSPA9 in hepatocellular carcinoma / 重庆医学

Objective To investigate the expression of HSPA9 in hepatocellular carcinoma(HCC) and its relationship with clinicopathological features and prognosis.Methods Forty-nine cases HCC treated by operative resection and follow up data in our hospital from January 2006 to January 2010 were retrospectively analyzed.Immunohistochemistry was performed to determine the expression of HSPA9 in HCC and paratumor tissues.The relationship between HSPA9 expression and clinicopathological features and prognosis was statistically analyzed.Results The HSPA9 protein expression in tumor tissue was higher that that in the paratumor tissue(t=6.601,P＜0.01),moreover the over expression of HSPA9 was significantly correlated with lymph node metastasis (P =0.005),TNM-stage(P =0.015),tumor differentiation (P =0.033),microvascular invasion (P =0.009) and recurrence (P =0.047).In the survival analysis results,the patients with over expression of HSPA9 had a much lower total survival rate(P=0.002)and much higher postoperative cumulative recurrence rate(P =0.003).There were significant differences in TNM-stage,microvascular invasion,lymph node metastasis,tumor differentiation and HSPA9 staining for overall survival and cumulative recurrence rate based on a univariate analysis(P＜0.05).Conclusion HSPA9 has over expression in HCC.The over expression of HS-PA9 is closely related to invasion and metastasis pathological features and can serve as an independent prognostic risk factor for predicting the prognosis of HCC.