The heteromeriselle complex typically adopts a heterohexameric arrangement, although variations such as heterotrimers and heterooctamers have been reported. Cryo-electron microscopy imaging has revealed that the catalytic subunit contains a Rossmann fold domain, while the regulatory subunit is enriched in alpha‑helical repeats that facilitate protein‑protein interactions. The interface between subunits is stabilized by a network of hydrogen bonds and salt bridges, which allow for rapid conformational changes in response to ligand binding.
Functional assays indicate that heteromeriselle complexes act as allosteric modulators of enzymatic activity. In the case of the serotonin transporter, the regulatory subunit of the heteromeriselle complex binds to phosphatidylinositol 4,5-bisphosphate, inducing a conformational shift that enhances serotonin reuptake. In other systems, heteromeriselle assemblies have been implicated in the regulation of kinase activity and the assembly of vesicular transport machinery.
Although the initial discovery of heteromeriselle complexes was purely descriptive, subsequent research has suggested that dysregulation of these complexes may contribute to neurological disorders such as autism spectrum disorders and certain cancers. Small‑molecule inhibitors that specifically target the inter-subunit interface of heteromeriselle complexes are currently in preclinical development as potential therapeutic agents.
The term heteromeriselle has gained traction in specialized literature, but it has not yet entered mainstream nomenclature. Some reviewers have called for a more systematic naming convention, arguing that the suffix "-iselle" is not consistent with the International Union of Biochemistry and Molecular Biology’s (IUBMB) protein nomenclature guidelines. As of 2025, the IUBMB has not formally adopted the term, and it remains a descriptor used primarily in recent journal articles and conference abstracts.