Original Research ARTICLE
A novel mutation in an NPXY motif of β integrin reveals phenotypes similar to him-4/hemicentin
- 1Baylor University, United States
Integrin, an αβ heterodimeric cell surface receptor for the extracellular matrix (ECM), carries two tyrosine phosphorylation motifs in the cytoplasmic tail of the β subunit. NPXY (Asn-Pro-x-Tyr) is a conserved tyrosine phosphorylation motif that binds to the phospho-tyrosine binding (PTB) domain. We generated a tyrosine to glutamic acid (E) mutation to modify tyrosine (Y) into a negatively charged amino NPXY in the βpat-3 integrin of Caenorhabditis elegans. The transgenic rescue animal displayed defects in gonad migration and tail morphology. Also, the mutant animals produced a high number of males, suggesting that the Y to E mutation in βpat-3 integrin causes a phenotype similar to that of Him mutant. Further analyses revealed that males of pat-3(Y804E) and him-4/hemicentin share additional phenotypes such as abnormal gonad and unsuccessful mating. A pat-3 transgenic rescue mutant with a non-polar phenylalanine (F) in NPXY, pat-3(Y792/804F), suppressed the high male number, defective mating, inviable zygote, and the abnormal gonad of him-4 mutants, indicating that Y to F mutation in both NPXY motifs suppressed the him-4 phenotypes.
This finding supports the idea that the ECM determines the activation state in integrin NPXY motifs; him-4/hemicentin may directly or indirectly interact with integrins and maintain the NPXY non-charged. Our findings provide new insight into a suppressive role of an ECM molecule in integrin NPXY activation.
Keywords: pat-3, Basement Membrane, negatively charged amino acid, Glutamic Acid, germ cell, Male mating, Somatic gonad, cell migration
Received: 28 Jun 2019;
Accepted: 08 Oct 2019.
Copyright: © 2019 Qiu, Sheesley, Ahn, Yu and Lee. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Myeongwoo Lee, Baylor University, Waco, 76798, Texas, United States, email@example.com