PIM-Related Kinases Selectively Regulate Olfactory Sensations in Caenorhabditis elegans

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• Mammalian PIM kinases are serine/threonine kinases involved in cell survival and motility.
• PIM kinases are expressed in sensory organs, including the olfactory epithelium, suggesting potential roles in sensory perception.

Purpose of the Study:

• To investigate the physiological roles of PIM kinases in the sensory organs of *Caenorhabditis elegans*.
• To determine if PIM-related kinases (PRKs) in *C. elegans* function as true PIM orthologs and their specific roles in sensory functions.

Main Methods:

• Utilized *Caenorhabditis elegans* as a model organism expressing two PIM-related kinases, PRK-1 and PRK-2.
• Administered pan-PIM inhibitors to assess effects on nematode sensory functions.
• Analyzed *prk*-deficient mutant strains to confirm findings.

Main Results:

• Demonstrated that *C. elegans* PRKs are true PIM orthologs with comparable substrate specificity and sensitivity to PIM inhibitors.
• Found that PRK activity is essential for olfactory sensation of repellents and attractants by AWB and AWC^ON neurons, but not for gustatory sensations.
• Identified PRK-1, but not PRK-2, as the key kinase regulating olfaction, supported by its expression in relevant head and tail neurons.

Conclusions:

• PRK-1 plays a critical, selective role in *C. elegans* olfaction.
• The findings suggest that PIM-related kinases may regulate mammalian olfaction due to evolutionary conservation.