Enlazin, a natural fusion of two classes of canonical cytoskeletal proteins, contributes to cytokinesis dynamics.
Cytokinesis requires a complex network of equatorial and global proteins to regulate cell shape changes. Here, using interaction genetics, we report the first characterization of a novel protein, enlazin. Enlazin is a natural fusion of two canonical classes of actin-associated proteins, the ezrin-radixin-moesin family and fimbrin, and it is localized to actin-rich structures. A fragment of enlazin, enl-tr, was isolated as a genetic suppressor of the cytokinesis defect of cortexillin-I mutants. Expression of enl-tr disrupts expression of endogenous enlazin, indicating that enl-tr functions as a dominant-negative lesion. Enlazin is distributed globally during cytokinesis and is required for cortical tension and cell adhesion. Consistent with a role in cell mechanics, inhibition of enlazin in a cortexillin-I background restores cytokinesis furrowing dynamics and suppresses the growth-in-suspension defect. However, as expected for a role in cell adhesion, inhibiting enlazin in a myosin-II background induces a synthetic cytokinesis phenotype, frequently arresting furrow ingression at the dumbbell shape and/or causing recession of the furrow. Thus, enlazin has roles in cell mechanics and adhesion, and these roles seem to be differentially significant for cytokinesis, depending on the genetic background.
Octtaviani
Edelyn
E
Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
Effler
Janet C
JC
Robinson
Douglas N
DN
D000595:Amino Acid Sequence; D000818:Animals; D001696:Biomechanical Phenomena; D002448:Cell Adhesion; D048708:Cell Growth Processes; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004023:Dictyostelium / Q000166:cytology* / Q000378:metabolism*; D020868:Gene Silencing; D008840:Microfilament Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010446:Peptide Fragments / Q000378:metabolism; D010641:Phenotype; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D010446:Peptide Fragments; D015800:Protozoan Proteins; C101109:ctxA protein, Dictyostelium discoideum