Robine MAFFO WOULEFACK, 29, is a dynamic young researcher with a passion for the life sciences. After obtaining a bachelor's degree in biochemistry in Cameroon, she pursued her academic career in France, where she obtained a master's degree in biochemistry, molecular biology and cell regulation at the University of Lorraine.

Driven by a deep interest in fundamental research, she then pursued a PhD in structural biochemistry and microbiology at the DynAMic UMR1128 laboratory under the supervision of Professor Nathalie Leblond and Dr Badreddine Douzi. She was awarded her doctorate from the University of Lorraine in December 2024.
She is currently serving as a Temporary Teaching and Research Assistant (ATER) position at the DynAMic laboratory -. Her research focuses on the study of the Type IV Secretion System (T4SS) in Gram-positive bacteria - a key mechanism mediating the conjugative transfer of mobile genetic elements between bacteria, and thus playing a central role in the spread of antibiotic resistance. Although the T4SS is widespread, particularly among diverse pathogens such as enterococci and streptococci, its architecture and mode of action remain poorly understood. Through her research, Dr Woulefack contributes to a better understanding of this system, opening new avenues for combatting the dissemination of antibiotic resistance.

Article references

Maffo-Woulefack R, Ali AM, Laroussi H, Cappèle J, Romero-Saavedra F, Ramia N, Robert E, Mathiot S, Soler N, Roussel Y, Fronzes R, Huebner J, Didierjean C, Favier F, Leblond-Bourget N, Douzi B. Elucidating assembly and function of VirB8 cell wall subunits refines the DNA translocation model in Gram-positive T4SSs. Sci Adv. 2025 Jan 24;11(4):eadq5975. doi: 10.1126/sciadv.adq5975. Epub 2025 Jan 22. PMID: 39841841; PMCID: PMC11753425.

Abstract

Bacterial type IV secretion systems (T4SSs) are widespread nanomachines specialized in the transport across the cell envelope of various types of molecules including mobile genetic elements during conjugation. Despite their prevalence in Gram-positive bacteria, including relevant pathogens, their assembly and functioning remain unknown. This study addresses these gaps by investigating VirB8 proteins, known to be central components of conjugative T4SSs in Gram-positive bacteria. However, the functional packing and precise role of VirB8 in T4SSs biology remain undefined. Our findings elucidate the nature of VirB8 proteins as cell wall components, where they multimerize and exhibit a conserved assembly pattern, distinct from VirB8 in Gram-negative bacteria. We also demonstrate that VirB8 proteins interact with other T4SS subunits and DNA, indicating their pivotal role in the building of the DNA translocation channel across the cell wall. We lastly propose a distinct architecture for conjugative T4SSs in Gram-positive bacteria compared to their Gram-negative counterparts, possibly attributed to the differences in the cell wall structure.