Actomyosin contraction during cellularization is regulated in part by Src64 control of Actin 5C protein levels

• Published in: Genesis (New York, N.Y. : 2000) Vol. 57; no. 6; pp. e23297 - n/a
• Main Authors: Carter, Tammy Y., Gadwala, Swetha, Chougule, Ashish B., Bui, Anh P. N., Sanders, Alex C., Chaerkady, Raghothama, Cormier, Nathaly, Cole, Robert N., Thomas, Jeffrey H.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-06-2019; Wiley Subscription Services, Inc
• Subjects: Actin; Actin 5C; Actin Cytoskeleton - metabolism; Actins - metabolism; Actomyosin; Actomyosin - metabolism; Actomyosin - physiology; Animals; Blastoderm; cellularization; Contraction; Cytoskeleton; Cytoskeleton - metabolism; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Drosophila Proteins - physiology; Embryo, Nonmammalian - metabolism; Embryos; Fruit flies; Levels; Microfilament Proteins - metabolism; Morphogenesis - genetics; Mutation; oxidative stress response; Protein-Tyrosine Kinases - genetics; Protein-Tyrosine Kinases - metabolism; Protein-Tyrosine Kinases - physiology; Proteins; Proteomics; Proteomics - methods; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins - physiology; Reduction; Regulators; Src64; cellularization; actin; Src64; oxidative stress response; proteomics; Actin 5C
• ISSN: 1526-954X; 1526-968X
• DOI: 10.1002/dvg.23297

Summary
Src64 is required for actomyosin contraction during cellularization of the Drosophila embryonic blastoderm. The mechanism of actomyosin ring constriction is poorly understood even though a number of cytoskeletal regulators have been implicated in the assembly, organization, and contraction of these microfilament rings. How these cytoskeletal processes are regulated during development is even less well understood. To investigate the role of Src64 as an upstream regulator of actomyosin contraction, we conducted a proteomics screen to identify proteins whose expression levels are controlled by src64. Global levels of actin are reduced in src64 mutant embryos. Furthermore, we show that reduction of the actin isoform Actin 5C causes defects in actomyosin contraction during cellularization similar to those caused by src64 mutation, indicating that a relatively high level of Actin 5C is required for normal actomyosin contraction and furrow canal structure. However, reduction of Actin 5C levels only slows down actomyosin ring constriction rather than preventing it, suggesting that src64 acts not only to modulate actin levels, but also to regulate the actomyosin cytoskeleton by other means.