Faiyaz Kasir Hasan | 2026 I.S. Symposium
Name: Faiyaz Kasir Hasan
Title: Starving to Build: The Role of Polyphosphate Kinase 1 in Development and Stress Response of Myxococcus xanthus
Major: Biochemistry and Molecular Biology
Minors: Economics; Statistical and Data Sciences
Advisor: Dean Fraga; Erzsebet Regan
Myxococcus xanthus is a soil bacterium with a remarkable survival strategy: when nutrients run out, cells work together to build multicellular fruiting bodies. I am fascinated by this system because it shows that even single-celled organisms can make complex collective decisions in response to stress. My project asks how cells manage their energy during this transition and whether that energy buffering helps determine successful development. I focused on two enzymes involved in energy homeostasis: polyphosphate kinase 1 (PPK1) and arginine kinase (AK). I hypothesized that PPK1 plays a vital role in helping cells respond to starvation and coordinate development even in the absence of AK, and vice versa. To evaluate this, I compared wild type, 螖PPK1, and 螖AK strains using starvation-induced fruiting-body assays, environmental stress response assays, and RNA-sequencing. The results suggest that PPK1 is important early in development. Cells lacking PPK1 showed inconsistent developmental outcomes, ranging from complete arrest to delayed formation of irregular fruiting bodies. RNA-seq further showed that 螖PPK1 differed most strongly from wild type at early time points, especially 8 hours after starvation, while 螖AK strains showed their strongest divergence at 32 hours. These suggest that PPK1 and AK do not function as fully redundant energy buffering enzymes but instead influence different stages of the starvation response. This supports the idea that energy buffering is closely tied to developmental decision-making in M. xanthus. Next steps include constructing a PPK1 and AK double deletion mutant to assess the phenotype and pathways that drive this developmental instability.
Posted in Symposium 2026 on May 1, 2026.
