Identification of the Rice Vacuolar ATPase B Subunit Gene and Its Expression Pattern Analysis Under Phosphorus Deficiency

A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR amplification. This gene encodes a polypeptide of 487 amino acid residues, containing a conservative ATP binding site and with a molecular weight of 54.06 kD and an isoelectric point of 4.99, southern analysis of the. genomic DNA indicates that V-ATPase B subunit is encoded by a single gene in rice genome. The amino acid homologies of V-ATPase B subunits among different organisms range from 76% to 97% and reveals that the evolution of V-ATPase B subunit is accompanied with the biological evolution. Expression pattern analysis indicated that the maximal expression of V-ATPase B subunit gene occurred at an early stage (6 - 12 h) after phosphorus starvation in roots, and lately stage (24 - 48 It) in leaves. Under phosphorus deficiency, the up-regulated expression of V-ATPase gene was presumed to strengthen the proton transport and provide the required energy to maintain an electrochemical gradient across the tonoplast to facilitate Phosphorus transport.

V-ATPase对肿瘤细胞糖酵解的影响

V-ATPase是一类特殊的膜转运蛋白,通过驱动质子转运以及参与信号转导调节细胞各种生理过程。V-ATPase在细胞中的主要功能及作用已有大量研究,而关于其激活或抑制对于细胞糖酵解的影响,以及在肿瘤细胞所起作用的相关材料比较零散。通过整理近年来关于V-ATPase以及肿瘤糖酵解等的相关文献发现,V-ATPase在肿瘤细胞发生、发展、转移等过程中起到了至关重要的作用。因此,总结V-ATPase的结构功能,以及其对细胞糖酵解的影响甚至在癌细胞中起的作用,有利于提高对于V-ATPase的进一步认识,并便于探索其在肿瘤治疗新方案,尤其靶向治疗研究中的作用。