CARMILs are large, multidomain, membrane-associated proteins that regulate actin assembly and Rho-family GTPases, but their role in inflammatory signaling is not defined. Tandem mass tag mass spectrometry indicated that, in fibroblasts, CARMIL1 associates with interleukin (IL)-1 signaling molecules. Immunoprecipitation of cells transfected with CARMIL1 mutants showed that the leucine-rich repeat (LRR) region of CARMIL1 associates with IL-1 receptor type 1 (IL-1R1) and IL-1 receptor-associated kinase (IRAK). Knockout of CARMIL1 by CRISPR-Cas9 reduced IL-1-induced ERK activation by 72% and MMP3 expression by 40%. Compared with CARMIL1 wild-type (WT), cells expressing mutant CARMIL1 lacking its LRR domain exhibited 45% lower ERK activation and 40% lower MMP3 expression. In fibroblasts transduced with a cell-permeable, TAT CARMIL1 peptide that competed with IL-1R1 and IRAK binding to the LRR of CARMIL1, collagen degradation was reduced by 43%. As the LRR of CARMIL1 evidently regulates IL-1 signaling, CARMIL1 could become a target for anti-inflammatory drug development.

CARMIL 是大的、多域的、膜相关蛋白，可调节肌动蛋白组装和 Rho 家族 GTP 酶，但它们在炎症信号传导中的作用尚未确定。串联质量标签质谱表明，在成纤维细胞中，CARMIL1 与白细胞介素 (IL)-1 信号分子相关联。转染 CARMIL1 突变体的细胞的免疫沉淀表明，CARMIL1 的富含亮氨酸重复序列 (LRR) 区域与 IL-1 受体 1 型 (IL-1R1) 和 IL-1 受体相关激酶 (IRAK) 相关。CRISPR-Cas9 敲除 CARMIL1 后，IL-1 诱导的 ERK 激活减少了 72%，MMP3 表达减少了 40%。与 CARMIL1 野生型 (WT) 相比，表达缺乏其 LRR 结构域的突变 CARMIL1 的细胞表现出 45% 的 ERK 激活降低和 40% 的 MMP3 表达降低。在用细胞渗透性转导的成纤维细胞中，TAT CARMIL1 肽与 IL-1R1 和 IRAK 竞争结合 CARMIL1 的 LRR，胶原蛋白降解减少了 43%。由于 CARMIL1 的 LRR 明显调节 IL-1 信号，因此 CARMIL1 可能成为抗炎药物开发的目标。