sumoylation

This term is a highly specialized technical noun used exclusively within molecular biology and biochemistry. It describes a specific post-translational modification, placing it in the same functional category as ubiquitination or phosphorylation. Because it refers to a biochemical process, it is used in a formal, scientific register and is almost never encountered in general conversation.

As a mass noun referring to a biological process, it is treated as uncountable. It does not typically take a plural form, as it describes the general mechanism of protein modification rather than individual instances of the event.