Rab4Rab11

Rab4Rab11 is a protein complex involved in intracellular trafficking and membrane dynamics, primarily associated with endosomal and lysosomal pathways. The complex is composed of two Rab GTPases, Rab4 and Rab11, which play distinct but complementary roles in cellular transport processes. Rab4 is predominantly involved in the recycling of receptors and vesicles from early endosomes back to the plasma membrane, facilitating rapid endocytic retrieval and membrane retrieval. Rab11, on the other hand, is crucial for the recycling of receptors from late endosomes or recycling endosomes to the trans-Golgi network and beyond, often directing cargo toward the cell surface or other organelles.

The interaction between Rab4 and Rab11 is regulated by a series of GTPase-activating proteins (GAPs), guanine nucleotide exchange factors (GEFs), and effectors that modulate their activity. Rab4Rab11 complexes are often found in specialized recycling endosomes, which are distinct from conventional endosomes in their ability to selectively sort and recycle specific cargo proteins. This selectivity is mediated by sorting receptors and adaptors that recognize cargo signals, ensuring efficient retrieval and reuse of membrane components.

Functionally, Rab4Rab11 pathways are essential for maintaining cellular homeostasis, particularly in processes like antigen presentation, receptor-mediated transport, and the response to extracellular signals. Dysregulation of these pathways has been linked to various diseases, including neurodegenerative disorders, cancer, and immune system dysfunctions. Understanding the precise mechanisms of Rab4Rab11 interaction continues to be a focus of research, as it holds potential for therapeutic interventions in conditions where disrupted trafficking contributes to pathology.