The MECP2 TRD domain interacts with the DNMT3A ADD domain at the H3 tail binding site

The DNMT3A DNA methyltransferase and MECP2 methylation reader are highly expressed in neurons. Both proteins interact via their DNMT3A ADD and MECP2 TRD domains, and the MECP2 interaction regulates the activity and subnuclear localization of DNMT3A. Here, we mapped the interface of both domains using peptide SPOT array binding, protein pull down, equilibrium peptide binding assays, and structural analyses. The region D529 D531 on the surface of the ADD domain was identified as interaction point with the TRD domain. This includes important residues of the histone H3 N terminal tail binding site to the ADD domain, explaining why TRD and H3 binding to the ADD domain is competitive. On the TRD domain, residues 214 228 containing K219 and K223 were found to be essential for the ADD interaction. This part represents a folded patch within the otherwise largely disordered TRD domain. A crystal structure analysis of ADD revealed that the identified H3 TDR lysine binding pocket is occupied by an arginine residue from a crystallographic neighbor in the ADD apoprotein structure. Finally, we show that mutations in the interface of ADD and TRD domains disrupt the cellular interaction of both proteins in NIH3T3 cells. In summary, our data show that the H3 peptide binding cleft of the ADD domain also mediates the interaction with the MECP2 TRD domain suggesting that this binding site may have a broader role also in the interaction of DNMT3A with other proteins leading to complex regulation options by competitive and PTM specific bindin

Swiss Community Pharmacies' on the Web and Pharmacists' Experiences with E-commerce: Longitudinal study and Internet-based questionnaire survey

BACKGROUND: There are multiple ways in which community pharmacies can present themselves on the Internet, e.g., as a platform for drug information or as an advertising platform for their services. OBJECTIVE: To estimate the number of Swiss community pharmacies on the Internet over the period of 32 months (2000-2003), to describe their current e-commerce services, and to explore the experiences and plans these pharmacies have with regard to their Internet presence. METHODS: A longitudinal study was performed to determine the number of Swiss German pharmacies on the Internet by conducting Internet searches in 2000, 2001, and 2003. In April 2002, a cross-sectional Internet-based survey was administered to explore the pharmacies' experiences and plans regarding their Web sites. RESULTS: As of April 2003, 373 (44%) of 852 community pharmacies from the German speaking part of Switzerland were on the Internet. One hundred eighty four listed an e-mail address and were asked to complete a questionnaire. Of the 107 pharmacies answering the survey questions (58% response rate): 46% had been on the Internet for 1 to 2 years; 33% of the Web sites are part of a pharmacy group's Web portal; 31% of the pharmacies plan to expand their Internet appearance in the future; 74% provide e-commerce services, with 81% of those pharmacies filling five or less orders per month; and 12% plan on expanding their e-commerce services in the future. CONCLUSIONS: The number of community pharmacies offering Internet services steadily increased over 32 months. Given the importance of the Internet as a tool for information, communication, and advertising for pharmacy products and services, it can be expected that the increase will continue. Pharmacy-group portals are important promoters of pharmacies on the Internet. For many community pharmacies, Internet portals that provide an Internet presence for the pharmacies and provide regularly-updated content (e.g., health news, tips, drug information) seem to be the most effective solutions. Even though 40% of the pharmacies already offer e-commerce services, these services are still of minor importance. For many pharmacists, the current legal regulations seem to be unclear. Most pharmacies want to maintain their Internet services