The present invention provides a human microtubule-associated protein (hLC3) and the polynucleotides which identify and encode hLC3. The invention also provides genetically engineered expression vectors, host cells, and a method for producing hLC3. The invention also provides hLC3 as well as agonists, antibodies, and antagonists of hLC3, and the use thereof for the prevention and treatment of diseases associated with the expression of hLC3. Additionally, the invention provides for the use of antisense molecules to polynucleotides encoding hLC3 for the treatment of diseases associated with the expression of hLC3. The invention also provides diagnostic assays which utilize the polynucleotide, or fragments or the complement thereof, and antibodies specifically binding hLC3.