| Description |
Cajal body (CB) contributes to the biogenesis of small nuclear RNPs (snRNPs), which are involved in pre-mRNA splicing. In addition to snRNPs, CBs also contain another type of RNP: small Cajal body-specific RNPs (scaRNPs). The presence of scaRNPs in the CB serves to modify the snRNA component of snRNPs. CBs also take part in the biogenesis of small nucleolar RNPs (snoRNPs). Like scaRNPs, there are 2 classes of snoRNPs: box H/ACA and box C/D. CBs also contain the RNP responsible for the formation of telomeres, telomerase. Along with snRNPs, scaRNPs and telomerase, the CB is enriched for many proteins[1]. Neuronal CBs concentrate coilin, fibrillarin, SMN (survival of motor neuron) and components of the splicing machinery indicating that they are canonical CBs potentially engaged in the assembly and maturation of spliceosomal snRNPs[2]. Fam118B was identified in a screen for coilin interacting proteins[1]. WRAP53β plays a central role in the maintenance of the nuclear organelles known as Cajal bodies, recruiting factors such as the SMN protein, scaRNAs and telomerase to these bodies[3]. Recent work has found that CB association with certain gene loci contributes to genome organization, especially of chromosome 1, and CBs impact the expression of many genes and RNA splicing. Since the CB plays an important role in the biogenesis of snRNP, scaRNP, snoRNP and telomerase, all of which are required for efficient and rapid cell proliferation, identification of signaling pathways that could be inhibited should be of therapeutic value in the treatment of cancer[1]. |