Interacting selectively with an opsonin, such as a complement component or antibody, deposited on the surface of a bacteria, virus, immune complex, or other particulate material.

negative regulation of virion penetration

Any process that stops, prevents or reduces the rate of the introduction of virus particles into the cell.

Combining with an opsonin to initiate a change in cell activity.

The chemical reactions involving pigment, any general or particular coloring matter in living organisms, e.g. melanin.

Catalysis of the reaction: L-tryptophan = tryptamine + CO2.

Any process that modulates the frequency, rate or extent of endocytosis.

Interacting selectively with any component or product of the complement cascade.

The chemical reactions involving eye pigments, any general or particular coloring matter in living organisms, found or utilized in the eye.

Catalysis of the reaction: acetyl-CoA + an aralkylamine = CoA + an N-acetylaralkylamine.

The change in morphology and behavior of a natural killer cell in response to a cytokine, chemokine, cellular ligand, pathogen, or soluble factor.

Any process that modulates the frequency, rate or extent of the formation of a daughter centriole of an existing centriole.

The process by which voltage-gated sodium and potassium become localized to distinct subcellular domains. Specific targeting, clustering, and maintenance of these channels in their respective domains are essential to achieve high conduction velocities of action potential propagation.

Interacting selectively with the C1q component of the classical complement cascade.

negative regulation of natural killer cell activity

Any process that stops, prevents or reduces the rate of natural killer cell activity.

clustering of voltage-gated sodium channels

clustering of voltage-dependent sodium channels

The process by which voltage gated sodium channels become localized together in high densities. In animals, nodes of Ranvier differ dramatically from internodal axonal regions in very high densities of voltage-dependent sodium (Nav) channels responsible for the rapid, inward ionic currents that produce membrane depolarization.