Capn11 is a gene encoding a calpain protein. Calpains are a superfamily of related proteins, some functioning as calcium-dependent cysteine proteases. The predicted Capn11 protein has typical calpain features like protease and calcium-binding domains. It is most closely related to CAPN1 and CAPN2 in mammals and may be the human orthologue of chicken micro/m calpain [1].

In mouse development, Capn11 mRNA is restricted to spermatocytes during later meiosis stages, indicating a role in spermatogenesis [2]. Evolutionarily, in pre-therian lineages, CAPN11 had a wide physiological function under strong purifying selection. However, in eutherians, there was an elevation in the d(N)/d(S) ratio, a shift to testis-specific regulation, and changes in its interaction with calpastatin, suggesting an evolved restricted physiological function in placental mammals [3]. In Atlantic halibut, Capn11 transcripts were widely detected across tissues, and in fast-twitch skeletal muscle, its transcript levels were lowest at maximal fasting and strongly upregulated with refeeding, indicating a role in regulating the balance between catabolism and growth in teleost skeletal muscle [4].

In summary, Capn11 has important functions in spermatogenesis and in regulating muscle metabolism in different species. Studies on mouse models and other species have revealed its tissue-specific expression patterns and roles in physiological processes, which may provide insights into related reproductive and muscle-related disease areas.

References:

1. Dear, T N, Möller, A, Boehm, T. . CAPN11: A calpain with high mRNA levels in testis and located on chromosome 6. In Genomics, 59, 243-7. doi:. https://pubmed.ncbi.nlm.nih.gov/10409436/

2. Dear, T N, Boehm, T. . Diverse mRNA expression patterns of the mouse calpain genes Capn5, Capn6 and Capn11 during development. In Mechanisms of development, 89, 201-9. doi:. https://pubmed.ncbi.nlm.nih.gov/10559499/

3. Macqueen, Daniel J, Delbridge, Margaret L, Manthri, Sujatha, Johnston, Ian A. 2010. A newly classified vertebrate calpain protease, directly ancestral to CAPN1 and 2, episodically evolved a restricted physiological function in placental mammals. In Molecular biology and evolution, 27, 1886-902. doi:10.1093/molbev/msq071. https://pubmed.ncbi.nlm.nih.gov/20223856/

4. Macqueen, Daniel J, Meischke, Lara, Manthri, Sujatha, Solberg, Christel, Johnston, Ian A. 2010. Characterisation of capn1, capn2-like, capn3 and capn11 genes in Atlantic halibut (Hippoglossus hippoglossus L.): Transcriptional regulation across tissues and in skeletal muscle at distinct nutritional states. In Gene, 453, 45-58. doi:10.1016/j.gene.2010.01.002. https://pubmed.ncbi.nlm.nih.gov/20093171/