Selfprotein

Selfprotein is a term used in some discussions to describe proteins that are produced by an organism and are considered part of its own biology, as opposed to proteins introduced from outside. The phrase is not standardized in the scientific literature, and its meaning changes with context. Broadly, selfprotein can refer to endogenous proteins involved in self-recognition, self-regulation, or maintenance of cellular homeostasis, and in some cases to proteins that are engineered to interact with a host’s own biosynthetic networks.

In immunology, selfproteins are endogenous proteins that are normally tolerated by the immune system. Central and peripheral tolerance prevent immune responses against selfproteins, and failure can lead to autoimmune disease where autoantigens are targeted by autoantibodies or autoreactive T cells.

In systems biology and biochemistry, selfproteins may refer to components that participate in feedback loops regulating their own expression or activity. Transcription factors often regulate their own promoters, and proteins can modulate pathways in which they are both regulator and substrate.

In synthetic biology and materials science, engineered selfproteins are designed to self-assemble into higher-order structures or to display self-recognition properties. Examples include self-assembling protein cages and programmable surface-binding proteins used in biomaterials and targeted therapeutics.

Study and verification rely on standard proteomics, genomics, and structural biology tools: mass spectrometry, RNA sequencing, chromatin immunoprecipitation, X-ray crystallography, cryo-electron microscopy, and interaction assays. Because the term is ambiguous, researchers typically define its scope explicitly in each publication.