Gene Ontology annotation through association of InterPro records with GO terms

InterPro IPR002641 (PNPLA domain) mapping assigns the generic "lipid metabolic process" to PATB1; patatin's activity is degradative, so the more specific "lipid catabolic process" is preferred.

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

Maps the UniProt keyword "Vacuole" to GO:0005773; consistent with primary immunocytochemical localization of patatin to tuber parenchyma vacuoles.

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

ARBA model assigns generic "lipase activity" to PATB1; the documented patatin function is a more specific glycerophospholipase / lipid acyl hydrolase.

GO_REF:0000043

Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping

SwissProt keyword-derived (SPKW) annotations present in the Sept 2025 goa_uniprot_gcrp snapshot but removed from the current GOA release after GOA retired the keyword2GO pipeline for cellular organisms.
For PATB1 the keywords "Storage protein" (-> nutrient reservoir activity) and "Lipid degradation" (-> lipid catabolic process) mapped to correct functions whose removal was collateral damage; the keyword "Plant defense" (-> defense response) mapped to an over-broad process given patatin's indirect, enzyme-mediated defense role.

file:SOLTU/PATB1/PATB1-uniprot.txt

UniProtKB entry P15476 (PATB1_SOLTU), Patatin-B1, Solanum tuberosum.

FUNCTION - "Probable lipolytic acyl hydrolase (LAH), an activity which is thought to be involved in the response of tubers to pathogens." SUBCELLULAR LOCATION - Vacuole. MISCELLANEOUS - patatin has a dual role as a somatic storage protein and as an enzyme involved in host resistance, and represents ~40% of total tuber protein.
Keywords - Glycoprotein, Hydrolase, Lipid degradation, Lipid metabolism, Plant defense, Signal, Storage protein, Vacuole. Domain - PNPLA (patatin) with GXSXG nucleophile motif (catalytic Ser77), DGA/G proton acceptor (Asp215) and a GGXR oxyanion hole; N-terminal 23-residue signal peptide and an N-glycosylation site.

file:SOLTU/PATB1/PATB1-deep-research-falcon.md

Deep-research report (falcon / Edison Scientific Literature) - functional annotation of potato PATB1 / Patatin-B1 (P15476).

Synthesizes Sonnewald et al. 1989 (immunocytochemistry), Shewry 2003 (tuber storage protein review) and Wu et al. 2025 (patatin systematic review), concluding PATB1 is a dual-function protein - a major vacuolar tuber storage glycoprotein (~40% of soluble tuber protein) and a lipid acyl hydrolase / phospholipase A-like serine hydrolase acting on a broad range of glycerolipids.
Patatin LAH releases free fatty acids and lysolipids from polar and neutral glycerolipids (mono-/diacylphospholipids, galactosyl diglycerides, mono-/diglycerides), with the protein deposited in tuber parenchyma vacuoles to sequester this membrane-active activity from cellular membranes.
Defense/host-resistance roles (suberin/wax precursor supply; inhibition of corn rootworm larvae and Phytophthora infestans) are indirect, mediated by fatty-acid release, and are largely inferred from broad patatin-family or mixed-isoform studies rather than direct PATB1 pathogen experiments.