Pietromonaco S F, Seluja G A, Aitken A, Elias L
Department of Medicine and the Cancer Center, University of New Mexico School of Medicine, Albuquerque 87131, USA.
Blood Cells Mol Dis. 1996;22(3):225-37. doi: 10.1006/bcmd.1996.0103.
The 14-3-3 proteins are involved in diverse signal transduction pathways and interact physically with a wide variety of proteins. Here, we report the partial sequence analysis of a human spleen 14-3-3 protein, which was identified as a variant form of the epsilon isoform. A peptide antibody generated to the variant 14-3-3 localizes in the centrosome and spindle apparatus of mouse leukemic FDCP cells by immunofluorescence microscopy. Immunoblots of centrosomes isolated by sucrose density gradient centrifugation of cell lysates disclose only the epsilon and gamma isoforms, while total cellular lysates contain the epsilon, gamma, beta and zeta isoforms of 14-3-3. These data suggest that a subset of total cellular 14-3-3 proteins are localized in the centrosomes and spindle apparatus. A differential localization of the centrosomal 14-3-3 was observed in mouse 3T3 cells. Serum-starved (quiescent) cells lack the centrosomal 14-3-3, but upon serum-stimulation of these quiescent cells, the centrosomal 14-3-3 reappears. We propose that a subset of intracellular 14-3-3 proteins are localized in the centrosome and spindle apparatus, and may in fact, link mitogenic signaling, the cell cycle, and perhaps the centrosome duplication cycle as well.
14-3-3蛋白参与多种信号转导途径，并与多种蛋白质发生物理相互作用。在此，我们报告了一种人脾脏14-3-3蛋白的部分序列分析，该蛋白被鉴定为ε亚型的一种变体形式。针对该变体14-3-3产生的肽抗体通过免疫荧光显微镜定位于小鼠白血病FDCP细胞的中心体和纺锤体装置。通过对细胞裂解物进行蔗糖密度梯度离心分离得到的中心体免疫印迹显示仅存在ε和γ亚型，而总细胞裂解物中含有14-3-3的ε、γ、β和ζ亚型。这些数据表明，总细胞14-3-3蛋白的一个亚群定位于中心体和纺锤体装置。在小鼠3T3细胞中观察到中心体14-3-3的差异定位。血清饥饿（静止）细胞缺乏中心体14-3-3，但在对这些静止细胞进行血清刺激后，中心体14-3-3重新出现。我们提出，细胞内14-3-3蛋白的一个亚群定位于中心体和纺锤体装置，实际上可能将促有丝分裂信号传导、细胞周期以及可能还有中心体复制周期联系起来。
