Leucine-rich repeat protein 1 (LRR1)

Leucine-rich repeat protein 1 (LRR1) is a leucine-rich repeat domain–containing protein. LRR motifs are common structural domains that form curved, horseshoe-shaped folds facilitating protein–protein interactions. LRR1 itself has been studied primarily in model organisms like *C. elegans*, where it functions as a nuclear component of the Cullin 2-RING E3 ligase complex, contributing to DNA replication integrity, cell cycle regulation, and genome stability[4]. There is currently no robust evidence that LRR1 (or its human orthologs/aliases such as PPIL5) acts as a druggable receptor, enzyme, or established therapeutic target in humans. Alternative names such as 4-1BB-mediated-signaling molecule or peptidylprolyl isomerase-like 5 refer to other protein family members, not directly to an established characterized human drug target. Many aliases appear to conflate unrelated proteins or computational predictions, and there is no evidence supporting therapeutic targeting of any LRR1 homolog in clinical practice or preclinical development[2][3][4]. **Note:** - The submitted target name and aliases appear to combine entries from basic structural biology (leucine-rich repeat proteins in general), gene predictions, and proteins of uncertain or undefined function. - No approved drugs or clinically actionable biomarkers are associated with this molecule/receptor. - It is not considered a human therapeutic target, receptor, kinase, or enzyme based on current knowledge. - Several aliases listed (e.g., PPIL5, peptidylprolyl isomerase-like 5) refer to distinct gene products and should not be combined as synonyms for LRR1 except following rigorous ortholog annotation. **Recommendation:** Care is warranted—the name "leucine rich repeat protein 1" or "LRR1" (sometimes confused with LRRK1/LRRK2 or with peptidylprolyl isomerases) does not map to a well-established human receptor or target suitable for drug development without further precise context and annotation. Human LRR1 is not currently regarded as a primary therapeutic target.[2][3][4]

Other names

Leucine-rich repeat protein 1LRR1PPIL5LRR-1MGC206894-1BB-mediated-signaling molecule4-1BBlrrLRR-repeat protein 1Peptidylprolyl isomerase-like 54-1BBLRRcyclophilin-like 5epididymis secretory sperm binding protein