IDENTIFICATION OF A PROTEIN ALTERED IN MUTANTS RESISTANT TO MICROTUBULE INHIBITORS AS A MEMBER OF THE MAJOR HEAT-SHOCK PROTEIN (HSP70) FAMILY

被引:45
作者
AHMAD, S [1 ]
AHUJA, R [1 ]
VENNER, TJ [1 ]
GUPTA, RS [1 ]
机构
[1] MCMASTER UNIV,DEPT BIOCHEM,HAMILTON L8N 3Z5,ONTARIO,CANADA
关键词
D O I
10.1128/MCB.10.10.5160
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A major cellular protein (P2; ≈ 70 kilodaltons) which is altered in Chinese hamster ovary (CHO) cell mutants resistant to the microtubule inhibitors colchicine and podophyllotoxin has been shown to correspond to the constitutive form of the 70-kilodalton heat shock protein (hsc70). The inference that P2 and hsc70 are the same protein is based on the following observations: (i) migration of P2 in two-dimensional polyacrylamide gels in the same position as that reported for hsc70; (ii) cross-reactivity of a monoclonal antibody which reacts with both the constitutive and induced forms of hsp70 with the P2 spot from wild-type CHO cells and with both P2 and a mutant form of P2 in a CHO cell mutant; (iii) specific reactivity of a polyclonal antibody to P2 with both the constitutive and heat-induced forms of hsp70 in human cells; (iv) identical immunofluorescent staining of dot/patchlike structures with both P2 and hsp70 antibodies in human and CHO cells; and (v) a cDNA clone for hsc70 has been isolated and sequenced from wild-type CHO cells. The in vitro transcription and translation product of this cDNA has been shown to comigrate with the P2 protein spot in two-dimensional gels, indicating their identity. The fact that there is an alteration in hsc70 in mutants resistant to antimitotic drugs suggests a role for this protein in the in vivo assembly and function of microtubules.
引用
收藏
页码:5160 / 5165
页数:6
相关论文
共 30 条