Nesprins (Nuclear envelope spectrin-repeat proteins) are a novel family of giant spectrin-repeat containing proteins. The nesprin-1 and nesprin-2 genes consist of 146 and 116 exons which encode proteins of ∼1mDa and ∼800 kDa is size respectively when all the exons are utilised in translation. However emerging data suggests that the nesprins have multiple alternative start and termination sites throughout their genes allowing the generation of smaller isoforms.
Rajgor, D., Mellad, J. A., Autore, F., Zhang, Q., & Shanahan, C. M. (2012). Multiple novel nesprin-1 and nesprin-2 variants act as versatile tissue-specific intracellular scaffolds. PLoS ONE, 7(7). https://doi.org/10.1371/journal.pone.0040098