Ruiz-Lafuente Natalia, Minguela Alfredo, Moraleda Jose M, Muro Manuel, Parrado Antonio
Department of Immunology, University Clinical Hospital Virgen de la Arrixaca-Biomedical Research Institute of Murcia (IMIB-Arrixaca), 30120 Murcia, Spain.
Department of Hematology, University Clinical Hospital Virgen de la Arrixaca-Biomedical Research Institute of Murcia (IMIB-Arrixaca), 30120 Murcia, Spain.
Antibodies (Basel). 2021 Aug 20;10(3):33. doi: 10.3390/antib10030033.
Dedicator-of-cytokinesis (DOCK), a family of guanine-nucleotide exchange factors (GEFs), comprises four subfamilies, named from A to D. DOCK-D comprises DOCK9, DOCK10, and DOCK11. The GEF activity involves translocation from the cytoplasm to the plasma membrane (PM), as assessed by the transfection of tagged proteins. However, the cellular localization of endogenous DOCK proteins is poorly understood. In this paper, to gain a better understanding of the role of the DOCK-D proteins, we studied their distribution between cytosol and nucleoplasm in 11 cell lines. DOCK-D proteins were distributed with variable cytosolic or nuclear predominance, although the latter was common for DOCK9 and DOCK11. These results suggest that the DOCK-D proteins may perform new nuclear functions, which remain to be discovered. Furthermore, we found that DOCK10 levels are increased by interleukin-4 (IL-4) in B-cell lymphoid neoplasms other than chronic lymphocytic leukemia (CLL) such as mantle cell lymphoma and diffuse large B-cell lymphoma. We also found evidence for an induction of the cytosolic levels of DOCK10 by IL-4 in CLL. Finally, we obtained a valid DOCK10 antiserum for immunofluorescence (IF) microscopy that, as an antibody against the hemagglutinin (HA) tag, marked PM ruffles and filopodia in HeLa cells with inducible expression of HA-DOCK10.
细胞分裂素激活蛋白（DOCK）是鸟嘌呤核苷酸交换因子（GEF）家族，包括四个亚家族，分别命名为A到D。DOCK-D包括DOCK9、DOCK10和DOCK11。通过转染标记蛋白评估，GEF活性涉及从细胞质向质膜（PM）的转位。然而，内源性DOCK蛋白的细胞定位了解甚少。在本文中，为了更好地理解DOCK-D蛋白的作用，我们研究了它们在11种细胞系的细胞质和核质之间的分布。DOCK-D蛋白的分布在细胞质或细胞核中占优势的情况各不相同，尽管后者在DOCK9和DOCK11中较为常见。这些结果表明，DOCK-D蛋白可能具有尚未被发现的新的核功能。此外，我们发现除慢性淋巴细胞白血病（CLL）外，如套细胞淋巴瘤和弥漫性大B细胞淋巴瘤等B细胞淋巴瘤中，白细胞介素-4（IL-4）可使DOCK10水平升高。我们还发现CLL中IL-4可诱导DOCK10的细胞质水平升高。最后，我们获得了一种用于免疫荧光（IF）显微镜检查的有效的DOCK10抗血清，作为针对血凝素（HA）标签的抗体，它可标记可诱导表达HA-DOCK10的HeLa细胞中的质膜褶皱和丝状伪足。
