Isoformok

Isoformok, or isoforms, are alternative protein products produced from the same gene. They arise primarily through alternative RNA processing, including splice variant formation, as well as alternative promoter usage and alternative polyadenylation. In some cases, changes such as RNA editing or different translation start sites can also contribute to distinct protein forms. These processes expand the functional repertoire of a single gene without requiring additional genes.

Isoformok can differ in amino acid sequence, domain composition, stability, subcellular localization, and interaction partners. Such differences allow isoforms to participate in different cellular pathways or to be required in specific tissues or developmental stages. While some isoforms have overlapping roles, others perform unique functions that are essential in particular contexts. Misregulation of isoform expression or the appearance of aberrant isoforms is associated with various diseases, including cancer and neurodegenerative disorders, making isoform expression a potential biomarker and therapeutic target.

Detection and annotation of isoformok rely on both transcript and protein data. RNA sequencing reveals transcript variants, while proteomics methods such as mass spectrometry confirm corresponding protein products. Annotation in gene databases (for example, RefSeq or Ensembl) assigns distinct identifiers to each isoform, often using gene symbols combined with transcript or protein IDs. Naming conventions vary by species and database, but the core idea is to distinguish the different products that originate from the same genetic locus.

Terminology notes: the term isoform refers to the different forms of a gene product, whereas paralogs refer to related genes within a genome. The broader concept proteoforms encompasses variations arising from sequence differences and post-translational modifications. In the Hungarian context, isoformok is the plural form of isoform.