fig1

Figure 1. Characteristics of MECP2 gene and its protein function. Note: (A) MECP2 gene subtypes, functional domains, and common mutation types (eight hotspot mutations). Two isoforms of the MECP2: MECP2-E1 (encoded by exons 1, 3, 4) and MECP2-E2 (encoded by exons 1, 3, 4). Red arrows indicate the transcription start sites (ATG) of the two isoforms. MeCP2 protein structure is composed of five major domains, N-terminal Domain (NTD), Methyl Binding Domain (MBD), Inter-Domain (ID), Transcription Repression Domain (TRD), and C-terminal Domain (CTD). The AT-Hook domain is located in the CTD, which allows binding to adenine-thymine (AT) rich DNA. Eight Hotspot Mutations: R106W (Arginine to Tryptophan), R133C (Arginine to Cystine), T158M (Threonine to Methionine), R168X (Arginine to termination codon), R255X (Arginine to termination codon), R294X (Arginine to termination codon), R270X (Arginine to termination codon), R306C (Arginine to Cystine); (B) Mechanisms through which MeCP2 regulates transcription, RNA splicing, and mRNA cleavage. The MBD and CTD domains of MeCP2 can activate or inhibit transcriptional regulation by binding to DNA. MeCP2 can regulate the alternative splicing of RNA by combining it with YB-1 and other proteins. MeCP2 can also regulate the expression of miRNAs through the interaction with the Dorsha complex. AT: adenine-thymine; CTD: C-terminal Domain; ID: Inter-Domain; MBD: Methyl Binding Domain; NTD: N-terminal Domain; TRD: Transcription Repression Domain.