Drosophila germ granules are assembled from protein components through different modes of competing interactions with the multi ‐domain Tudor protein

Protein components of the germ granules, Aubergine (Aub) and Pyruvate Kinase (PyK), use different modes to associate with Tudor (Tud) protein, which contains 11 Tud domains. Aub binds to a single Tud domain and PyK requires two Tud domains. Aub and PyK compete for binding to Tudin vitro and form separate clusters within a granulein vivo, thereby minimizing the competition. Membraneless organelles are RNA –protein assemblies which have been implicated in post-transcriptional control. Germ cells form membraneless organelles referred to as germ granules, which contain conserved proteins including Tudor domain-containing scaffold polypeptides and their partner proteins that interact with Tudor domains . Here, we show that inDrosophila, different germ granule proteins associate with the multi-domain Tudor protein using different numbers of Tudor domains. Furthermore, these proteins compete for interaction with Tudorin vitro and, surprisingly, partition to distinct and poorly overlapping clusters in germ granulesin vivo. This partition results in minimization of the competition. Our data suggest that Tudor forms structurally different configurations with different partner proteins which dictate different biophysical properties and phase separation parameters within the same granule.

Source: FEBS Letters - March 19, 2024 Category: Biochemistry Authors: Wahiduzzaman, Samuel J. Tindell, Emma Alexander, Ethan Hackney, Kabita Kharel, Ryan Schmidtke, Alexey L. Arkov Tags: Research Letter Source Type: research