Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Starkville, MS, USA.
Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden; Department of Biology, Lund University, Lund, Sweden.
Curr Biol. 2021 Jul 26;31(14):3073-3085.e3. doi: 10.1016/j.cub.2021.04.076. Epub 2021 Jun 1.
Integrins are transmembrane receptors that activate signal transduction pathways upon extracellular matrix binding. The integrin-mediated adhesive complex (IMAC) mediates various cell physiological processes. Although the IMAC was thought to be specific to animals, in the past ten years these complexes were discovered in other lineages of Obazoa, the group containing animals, fungi, and several microbial eukaryotes. Very recently, many genomes and transcriptomes from Amoebozoa (the eukaryotic supergroup sister to Obazoa), other obazoans, orphan protist lineages, and the eukaryotes' closest prokaryotic relatives, have become available. To increase the resolution of where and when IMAC proteins exist and have emerged, we surveyed these newly available genomes and transcriptomes for the presence of IMAC proteins. Our results highlight that many of these proteins appear to have evolved earlier in eukaryote evolution than previously thought and that co-option of this apparently ancient protein complex was key to the emergence of animal-type multicellularity. The role of the IMACs in amoebozoans is unknown, but they play critical adhesive roles in at least some unicellular organisms.
整联蛋白是一种跨膜受体，在与细胞外基质结合后会激活信号转导途径。整联蛋白介导的黏附复合物（IMAC）介导各种细胞生理过程。虽然 IMAC 被认为是动物特有的，但在过去的十年中，这些复合物在 Obazoa 的其他谱系中被发现，Obazoa 包含动物、真菌和几个微生物真核生物。最近，来自变形虫门（Obazoa 的真核超级群姐妹群）、其他 Obazoa、孤儿原生生物谱系以及真核生物最近的原核亲属的许多基因组和转录组已经可用。为了提高 IMAC 蛋白存在和出现的位置和时间的分辨率，我们调查了这些新获得的基因组和转录组中是否存在 IMAC 蛋白。我们的结果表明，这些蛋白质中的许多似乎在真核生物进化中比以前认为的更早进化，并且这种古老的蛋白质复合物的共选择是动物型多细胞性出现的关键。IMAC 在变形虫门中的作用尚不清楚，但它们在至少一些单细胞生物中发挥着关键的黏附作用。
