Biological Science Research Center, Southwest University, Chongqing 400716, China; Chongqing Key laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing 400716, China.
Biological Science Research Center, Southwest University, Chongqing 400716, China; State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Chongqing Key laboratory of Sericultural Science, Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing 400716, China.
Int J Biol Macromol. 2019 Jul 1;132:1121-1130. doi: 10.1016/j.ijbiomac.2019.03.166. Epub 2019 Mar 27.
Sericins are large proteins with molecular weights >70 kDa. Three sericin genes were reported in the silkworm, including sericin 1, sericin 2 and sericin 3. In this study, we have identified a new sericin gene and designated it as sericin 4. The sequence, exon-intron structure, alternative splicing, and translation products of this gene have been described in this study. Quantitative RT-PCR analysis indicates that sericin 4 is expressed in the middle silk gland. Immunofluorescence results show co-localization of sericin 1 and sericin 4 in the MSG. Western blot analysis revealed that sericin 4 was found in the larval silk produced from the second instar to the fourth instar. Two protein bands at approximately 280 kDa and 260 kDa, were detected by western blot for sericin 4. Two repetitive motifs that are rich in charged amino acids and glutamine have been identified, and they are likely to be responsible for the adhesiveness of sericin 4. Overall, this study identifies a novel biological adhesive protein and provides new information for understanding how sericins contribute to the adhesive properties of larval silks.
丝胶蛋白是一种分子量大于 70kDa 的大型蛋白质。在蚕中报道了三种丝胶基因，包括丝胶 1、丝胶 2 和丝胶 3。在本研究中，我们鉴定了一个新的丝胶基因，并将其命名为丝胶 4。本研究描述了该基因的序列、外显子-内含子结构、选择性剪接和翻译产物。定量 RT-PCR 分析表明丝胶 4 在中丝腺中表达。免疫荧光结果显示丝胶 1 和丝胶 4 在 MSG 中存在共定位。Western blot 分析显示丝胶 4 存在于从第二龄到第四龄幼虫产生的丝中。Western blot 检测到丝胶 4 的两个约 280kDa 和 260kDa 的蛋白条带。鉴定出两个富含带电氨基酸和谷氨酰胺的重复基序，它们可能负责丝胶 4 的粘性。总的来说，本研究鉴定了一种新型生物黏附蛋白，为了解丝胶如何有助于幼虫丝的黏附特性提供了新的信息。
