Transgelin is an actin cross‐linking/gelling protein of the calponin family, which is associated with actin stress fibres, cell motility, adhesion and the maintenance of cell morphology. Transgelin‐like proteins (TLPs) have also been identified as shell matrix proteins (SMPs) in several mollusc species; however, the functions of TLPs in biomineralization remain unknown. Transgelin‐like protein 1 (TLP‐1) was previously identified from the shell of Mytilus coruscus as a novel 19 kDa SMP with a calponin homology (CH) domain. To understand the role of TLP‐1 in shell formation, the expression level and localization of the TLP‐1 gene in biomineralization‐related tissues were determined in this study. Furthermore, recombinant TLP‐1 was expressed in a prokaryotic expression system with codon optimization, and an anti‐rTLP‐1 antibody was prepared based on the expressed recombinant TLP‐1 (rTLP‐1) protein. In vitro, rTLP‐1 induced the formation of CaCO₃ polymorphic crystals with distinct morphologies and inhibited crystallization rate and crystal interactions. Immunohistochemical, immunofluorescence, and pull‐down analyses using the anti‐rTLP‐1 antibody revealed the specific locations of TLP‐1 in biomineralization‐related tissues and shell myostracum layer, and suggested the existence of a possible TLP‐1 interaction network in the shell matrix. Our results are beneficial for understanding the functions of TLP‐1, particularly through its CH domain, during shell mineralization.

中文翻译：

---

来自 Mytilus 壳的重组 transgelin 样蛋白 1 在体外诱导 CaCO3 多晶型晶体的形成。

Transgelin 是一种钙调蛋白家族的肌动蛋白交联/凝胶蛋白，与肌动蛋白应力纤维、细胞运动、粘附和细胞形态的维持有关。Transgelin 样蛋白 (TLP) 也已被鉴定为几种软体动物中的壳基质蛋白 (SMP)；然而，TLPs 在生物矿化中的功能仍然未知。Transgelin 样蛋白 1 (TLP-1) 之前是从Mytilus coruscus的壳中发现的作为具有钙调蛋白同源 (CH) 结构域的新型 19 kDa SMP。为了了解 TLP-1 在贝壳形成中的作用，本研究确定了 TLP-1 基因在生物矿化相关组织中的表达水平和定位。此外，重组TLP-1在密码子优化的原核表达系统中表达，并基于表达的重组TLP-1（rTLP-1）蛋白制备抗rTLP-1抗体。在体外，rTLP-1 诱导 CaCO _3的形成具有不同形态和抑制结晶速率和晶体相互作用的多晶型晶体。使用抗 rTLP-1 抗体的免疫组织化学、免疫荧光和下拉分析揭示了 TLP-1 在生物矿化相关组织和壳肌层中的特定位置，并表明壳中可能存在 TLP-1 相互作用网络矩阵。我们的结果有助于理解 TLP-1 在壳矿化过程中的功能，特别是通过其 CH 结构域。