Homoserine is produced from aspartate via aspartate-4-semialdehyde, which is produced from β-phosphoaspartate. By the action of homoserine dehydrogenases, the semialdehyde is converted to homoserine.
-Homoserine is substrate for homoserine kinase, yielding phosphohomoserine (homoserine-phosphate), which is converted to by threonine synthase to yield -threonine.
Homoserine is converted to O-succinyl homoserine by homoserine O-succinyltransferase, a precursor to -methionine.
Homoserine allosterically inhibits aspartate kinase and glutamate dehydrogenase. Glutamate dehydrogenase  reversibly converts glutamate to α-ketoglutarate and α-ketoglutarate coverts to oxaloacetate through the citric cycle. Threonine acts as another allosteric inhibitor of aspartate kinase and homoserine dehydrogenase, but it is a competitive inhibitor of homoserine kinase.