Christyne Nwakanma
Research Mentor(s): Ruma Banerjee
Mentor Department: Biological Chemistry
Authors: Christyne Nwakanma, Li Zhu, Dr. Ruma Banerjee
Session: Session 5 (2:00pm – 2:50pm)
Presentation Type: Poster 102
Abstract
Vitamin B12 is an essential nutrient that is obtained primarily through diet, and plays a critical role in cellular metabolism. B12 deficiency can lead to severe health issues. Vitamin B12 is trafficked via a complex pathway that facilitates the utilization of B12 in the cytoplasm and mitochondria in our cells, and supports DNA and amino acid synthesis. The CblD protein acts as a B12 chaperone, directing the cofactor to either cytoplasmic or mitochondrial branches of the trafficking pathway. Mutations in the mmadhc gene, which encodes CblD, disrupts this process and causes diseases such as combined or isolated methylmalonic aciduria and homocystinuria. The aim of this study was to investigate the mechanisms regulating CblD stability in the cytoplasm. To this end, we performed mutagenesis on CblD, targeting lysine residues near the N-terminus, to assess their potential role in targeting the protein for proteasomal degradation following ubiquitination. By identifying key lysines that modulate CblD stability, our data supports the role of the ubiquitination pathway in regulating CblD levels in the cytoplasm.
