Ptp2like

Ptp2like is a term used in protein-domain classification to denote proteins that contain a catalytic phosphatase domain homologous to yeast Ptp2. It is not a single gene but a collection of related sequences identified by similarity to the PTP2 catalytic domain across diverse organisms. Members of the group are typically annotated by automated pipelines as putative protein tyrosine phosphatases, though functional validation is variable.

Structural features commonly include a conserved PTP catalytic motif within a roughly 250–300 amino acid domain, often containing the HCX5R motif that includes the catalytic cysteine. Many Ptp2like proteins lack the extensive regulatory tails seen in classical protein tyrosine phosphatases; some also possess additional domains such as SH2-like regions, transmembrane segments, or localization signals that can influence regulation and localization.

Functionally, Ptp2like proteins are predicted to act as phosphatases based on sequence homology, capable of removing phosphate groups from phosphotyrosine residues and, in some cases, from phosphoserine or phosphothreonine. Substrate specificity and physiological roles remain poorly defined and appear to vary by organism. In plants and fungi, putative Ptp2like enzymes have been proposed to participate in signaling pathways related to development, stress responses, and immunity; in other lineages, supporting evidence is limited to in vitro activity.

Nomenclature and databases note that the label “Ptp2like” groups sequences by shared catalytic-domain architecture rather than strict orthology. Users should consult organism-specific annotations and experimental data for confirmation of function and relevance to particular pathways. See also protein tyrosine phosphatase, PTP family, and dual-specificity phosphatases.