Various N-terminal tags have often been used to identify the functions and localization of Rab small GTPases, but their impact on Rab proteins themselves has been poorly investigated. Here, we used a knockout (KO)–rescue approach to systematically evaluate the effect of N-terminal tagging of two Rabs, Rab10 and Rab27A, on Rab10-KO HeLa cells and Rab27A-deficient melanocytes (melan-ash cells), respectively. The results showed that all of the N-terminal-tagged Rab27A proteins mediated actin-based melanosome transport in the melan-ash cells, but none of the N-terminal-tagged Rab10 proteins fully rescued the defect in tubular endosome formation in the Rab10-KO cells. Although the N-terminal-tagged Rab10 proteins had the ability to localize tubular endosomes in wild-type HeLa cells, they sometimes exhibited a dominant-negative effect on tubular endosome formation. We also found that a conserved lysine residue at amino acid position 3 (K3) in the Rab10 proteins of different species is required for tubular endosome formation. Thus, it will be important to determine whether other Rab isoforms with N-terminal tags behave similarly to their corresponding untagged isoforms by performing appropriate KO–rescue experiments in future studies.
The conserved K3 residue in the N-terminal region of Rab10 small GTPase is required for tubular endosome formation: N-terminal tagging causes Rab10 dysfunction
Call for papers - Cilia and Flagella: from Basic Biology to Disease
We are welcoming submissions for our upcoming special issue: Cilia and Flagella: from Basic Biology to Disease. This issue will be coordinated by two Guest Editors: Pleasantine Mill (University of Edinburgh) and Lotte Pedersen (University of Copenhagen). Submission deadline: 1 March 2025.
Biologists @ 100 - join us in Liverpool in March 2025
We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register your interest to join us in March 2025 in Liverpool, UK. The deadline for abstract submission and early-bird registration is 17 January 2025.
Fantastic proteins and where to find them – histones, in the nucleus and beyond
In this Review, Johanna Grinat and colleagues provide an evolutionary perspective of histones, nuclear chromatin and extracellular chromatin biology, describing the known extranuclear and extracellular functions of histones.
JCS-FocalPlane Training Grants
Early-career researchers - working in an area covered by JCS - who would like to attend a microscopy training course, please apply. Deadline dates for 2025 applications: 7 March 2025 (decision by week commencing 21 April 2025) and 6 June 2025 (decision by week commencing 28 July 2025).
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