SUMOylation primarily affects which aspects of protein function?

SUMOylation specifically refers to the process where a small ubiquitin-like modifier (SUMO) is attached to a protein, influencing its function, localization, and interactions within the cell. One of the primary effects of SUMOylation is on transcriptional regulation and nuclear transport. When proteins involved in these processes are SUMOylated, they can alter gene expression by modulating the activity of transcription factors and other regulatory proteins.

Additionally, SUMOylation plays a critical role in the transport of proteins into and out of the nucleus. By attaching SUMO moieties, proteins can exhibit changes in their localization, often promoting nuclear import of certain proteins that function in transcription, while also affecting their stability or interactions with other nuclear factors.

In contrast, while protein degradation, protein synthesis, and signal transduction can be influenced by various post-translational modifications, they are not the primary roles associated with SUMOylation. SUMO may have indirect effects on these processes through its impact on transcriptional and transport mechanisms, but the direct relationship and significance of SUMOylation are most evident in transcriptional regulation and nuclear transport.