The cellular process in which a signal is conveyed to trigger a change in the activity or state of a cell. Signal transduction begins with reception of a signal (e.g. a ligand binding to a receptor or receptor activation by a stimulus such as light), or for signal transduction in the absence of ligand, signal-withdrawal or the activity of a constitutively active receptor. Signal transduction ends with regulation of a downstream cellular process, e.g. regulation of transcription or regulation of a metabolic process. Signal transduction covers signaling from receptors located on the surface of the cell and signaling via molecules located within the cell. For signaling between cells, signal transduction is restricted to events at and within the receiving cell.

The set of specific processes that generate the ability of an organism to induce an abnormal, generally detrimental state in another organism.

The process in which proteins are transferred into the extracellular milieu or directly into host cells by the bacterial type III secretion system; secretion occurs in a continuous process without the distinct presence of periplasmic intermediates and does not involve proteolytic processing of secreted proteins.

A cellular process that results in the biosynthesis of constituent macromolecules, assembly, and arrangement of constituent parts of a cell wall. Includes biosynthesis of constituent macromolecules, such as proteins and polysaccharides, and those macromolecular modifications that are involved in synthesis or assembly of the cellular component. A cell wall is the rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal and most prokaryotic cells, maintaining their shape and protecting them from osmotic lysis.

A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of the cell envelope, everything external to, but not including, the cytoplasmic membrane of bacteria, encompassing the periplasmic space, cell wall, and outer membrane if present.

The hydrolysis of proteins into smaller polypeptides and/or amino acids by cleavage of their peptide bonds.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

An envelope that surrounds a bacterial cell and includes the cytoplasmic membrane and everything external, encompassing the periplasmic space, cell wall, and outer membrane if present.

The region between the inner (cytoplasmic) and outer membrane (Gram-negative Bacteria) or cytoplasmic membrane and cell wall (Fungi and Gram-positive Bacteria).