Lsm11-flox Mouse

Lsm11, a component of the replication-dependent histone pre-mRNA-processing complex, is crucial for the 3' end processing of metazoan replication-dependent histone pre-mRNAs [1,2,3,4,5,6,7]. U7 snRNP, in which Lsm11 is a part, is distinct from spliceosomal snRNPs as it lacks Sm subunits D1 and D2 and contains Lsm10 and Lsm11 instead [2,3]. Lsm11 is involved in pathways related to histone metabolism and is of great biological importance as histone pre-mRNA processing is essential for proper chromatin structure and cell function [1,2,3,4,5,6,7]. Genetic models, such as Drosophila models, have been valuable for studying Lsm11's function [4,7].

In Drosophila, mutations in Lsm11 disrupt normal histone pre-mRNA processing, leading to the production of poly(A)+ histone mRNA due to transcriptional read-through to cryptic polyadenylation sites [7]. A two-amino-acid mutation of Drosophila Lsm11 that prevents its binding to FLASH (a processing factor that binds Lsm11) cannot rescue the lethality or histone pre-mRNA processing defects resulting from an Lsm11 null mutation, indicating the importance of this interaction for histone pre-mRNA processing in vivo and for proper development and viability in flies [4]. In human, biallelic mutations in Lsm11 are associated with Aicardi-Goutières syndrome, a rare monogenic autoimmune disease. These mutations lead to misprocessing of canonical histone transcripts, disturbance of linker histone stoichiometry, altered distribution of nuclear cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS), and enhanced interferon signaling mediated by the cGAS-stimulator of interferon genes (STING) pathway [1].

In conclusion, Lsm11 is essential for histone pre-mRNA processing, which is vital for maintaining proper chromatin structure and normal cellular function. Model-based research, especially in Drosophila, has revealed its role in development and viability. In humans, its malfunction due to mutations is associated with Aicardi-Goutières syndrome, highlighting its significance in understanding this autoimmune disease.