What factors contribute to proteome diversity?

Post-translational modification, alternative splicing, DNA mutations

Explanation:

The diversity of the proteome can occur at different levels of biological processes:

1. During DNA replication yielding DNA mutations.

2. At the mRNA level in Alternative Splicing.

3. After translation on amino acid molecules including addition of different types of sugars (Glycosylation). This is post-translational modification.