RASSFIA interacts with microtubule-associated proteins and modulates microtubule dynamics
RASSFIA interacts with microtubule-associated proteins and modulates microtubule dynamics
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DOI：
10.1158/0008-5472.can-04-0267
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发表时间：
2004-06-15
期刊：
影响因子：
11.2
通讯作者：
Latif, F
中科院分区：
文献类型：
--
作者：
Dallol, A;Agathanggelou, A;Latif, F
候选肿瘤抑制基因RASSF1A在许多类型的成人和儿童癌症中失活。然而，RASSF1A发挥其肿瘤抑制功能的机制尚未阐明。为此，我们进行了酵母双杂交筛选，以在人脑cDNA文库中鉴定新的rassf1a相互作用蛋白。70%的相互作用克隆与微管相关蛋白具有同源性，包括MAP1B和VCY2IP1/C19ORF5。随后在哺乳动物细胞系中证实了RASSF1A与MAP1B和VCY2IP1/C19ORF5的关联。这表明RASSF1A可能通过与微管相互作用发挥其肿瘤抑制功能。我们证明RASSF1A与微管结合，导致它们以超稳定的圆形束存在。我们发现，在RASSF1A编码区，C65R和R257Q两个自然发生的肿瘤相关错义替换，扰乱了RASSF1A与微管的关联。除了VCY2IP1/C19ORF5外，C65R和R257Q诱导微管乙酰化的能力降低，并且不能保护微管免受诺可达唑的解聚作用。此外，野生型RASSF1A能够阻断DNA合成，而不是C65R或R257Q。我们的数据确定了RASSF1A在调节微管和细胞周期动力学中的作用，这可能是RASSF1A对癌细胞施加生长抑制的机制的一部分。
The candidate tumor suppressor gene RASSF1A is inactivated in many types of adult and childhood cancers. However, the mechanisms by which RASSF1A exerts its tumor suppressive functions have yet to be elucidated. To this end, we performed a yeast two-hybrid screen to identify novel RASSF1A-interacting proteins in a human brain cDNA library. Seventy percent of interacting clones bad homology to microtubule-associated proteins, including MAP1B and VCY2IP1/C19ORF5. RASSF1A association with MAP1B and VCY2IP1/C19ORF5 was subsequently confirmed in mammalian cell lines. This suggested that RASSF1A may exert its tumor-suppressive functions through interaction with the microtubules. We demonstrate that RASSF1A associates with the microtubules, causing them to exist as hyperstabilized circular bundles. We found that two naturally occurring tumor-associated missense substitutions in the RASSF1A coding region, C65R and R257Q, perturb the association of RASSF1A with the microtubules. The C65R and R257Q in addition to VCY2IP1/C19ORF5 showed reduced ability to induce microtubule acetylation and were unable to protect the microtubules against the depolymerizing action of nocodazole. In addition, wild-type RASSF1A but not the C65R or the R257Q is able to block DNA synthesis. Our data identify a role for RASSF1A in the regulation of microtubules and cell cycle dynamics that could be part of the mechanism(s) by which RASSF1A exerts its growth inhibition on cancer cells.