Chromatin reader protein, involved in positively modulating the rate of age-related behavioral deterioration (PubMed:32103178). Positively modulates the level of global trimethylated 'Lys-9' of histone H3 (H3K9me3), but not of H3K9me2 or H3K9me1 (PubMed:32103178). May repress the expression of mitochondrial function-related genes by occupying their promoter regions, working in concert with histone methyltransferase, set-6 (PubMed:32103178). Involved in modulation of the mitochondrial unfolded protein response (UPR) (PubMed:32103178). Negatively regulates expression of bas-1, a serotonin (5-HT) and dopamine synthesizing enzyme (DOPA decarboxylase), with aging (PubMed:32103178). Negatively modulates levels of endogenous 5-HT and dopamine with aging (PubMed:32103178). Involved in modulating longevity, probably as a result of enhanced stress resistance via mechanisms related to dietary restriction and mitochondrial function (PubMed:32103178). Interacts with set-6. Broadly expressed in the nervous system, including head, body and tail neurons. Expression increases with age. RNAi-mediated knockdown prevents age-related decline in the expression of bas-1, a serotonin (5-HT) and dopamine synthesizing enzyme (DOPA decarboxylase) (PubMed:32103178). RNAi-mediated knockdown improves behavioral performance in pharyngeal pumping in aged worms (PubMed:32103178). Belongs to the WAL family.