Das S, Deb T B, Kumar R, Datta K
Biochemistry Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
Gene. 1997 Apr 29;190(1):223-5. doi: 10.1016/s0378-1119(97)00035-8.
We have already reported that human fibroblast 34-kDa hyaluronic acid-binding protein (HABP) is identical with P32, the protein co-purified with splicing factor SF-2 [Deb and Datta (1996) J. Biol. Chem. 271, 2206-2212]. Data search further revealed that it has 92% sequence homology with a murine protein YL2 which interacts with HIV1 Rev. In this paper we have successfully demonstrated that HIV1 Rev binds with labeled 34-kDa HABP which can be competed with excess unlabeled HABP, suggesting this protein can be a cellular factor promoting HIV1 Rev to function. Interestingly, the multifunctional nature of HABP has been elucidated as it has 100% homology with another protein gC1q, the complement protein. The distinct non-overlapping binding motifs for HA and gC1q have been identified in the same protein, suggesting that either the protein can function independently or its activity is regulated by ligand binding, wherein its binding to one of the ligands may modulate the receptor activity of the other ligand.
我们已经报道过，人成纤维细胞34 kDa透明质酸结合蛋白（HABP）与P32相同，P32是与剪接因子SF-2共纯化的蛋白质[Deb和Datta（1996年）《生物化学杂志》271, 2206 - 2212]。进一步的数据检索显示，它与一种与HIV-1 Rev相互作用的鼠蛋白YL2有92%的序列同源性。在本文中，我们成功证明HIV-1 Rev与标记的34 kDa HABP结合，且这种结合可被过量未标记的HABP竞争，这表明该蛋白可能是促进HIV-1 Rev发挥功能的一种细胞因子。有趣的是，HABP的多功能性质已被阐明，因为它与另一种蛋白gC1q（补体蛋白）有100%的同源性。在同一蛋白中已鉴定出针对透明质酸和gC1q的不同且不重叠的结合基序，这表明该蛋白要么能独立发挥功能，要么其活性受配体结合调节，其中它与一种配体的结合可能会调节另一种配体的受体活性。
