A specific integrin αPS3βPS1 heterodimer is required for hemocyte phagocytosis in Chinese mitten crab, Eriocheir

Rongping Wang1, Chengyu Lv1, Junfeng Hou1

  • 1Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, 201306, China.

Integrins are evolutionarily conserved adhesion receptors that play pivotal roles in phagocytosis across metazoans, yet the specific αβ heterodimers involved in crustacean cellular immunity remain poorly defined. In this study, we identified and characterized an integrin α subunit, designated integrin αPS3 (EsITGAPS3), from the economically important Chinese mitten crab, Eriocheir sinensis. Bioinformatic analyses revealed that EsITGAPS3 shares structural similarity with arthropod integrin αPS3/αPS4/αPS5 subfamily members but exhibits low sequence conservation across distant taxa. EsITGAPS3 was ubiquitously expressed in crab tissues, with the highest levels in immune-relevant organs, including hemocytes, hepatopancreas, and gills. Its transcription was significantly induced in hemocytes following in vitro challenge with Vibrio parahaemolyticus. Functional knockdown of EsITGAPS3 via RNA interference markedly impaired hemocyte phagocytosis of FITC-labeled bacteria, demonstrating its important role in antibacterial cellular immunity. Using AlphaFold-based structural prediction, we identified integrin βPS-like subunit integrin βPS1 (EsITGBPS1) as the top-ranked candidate β partner for EsITGAPS3, and co-immunoprecipitation confirmed their physical interaction and heterodimer formation. Importantly, RNAi-mediated silencing of EsITGBPS1 similarly compromised bacterial phagocytosis, indicating that the integrin αPS3βPS1 (EsITGAPS3-EsITGBPS1) heterodimer functions as a key receptor complex in crab hemocytes. Our findings define a specific integrin αPS3βPS1 pair required for efficient phagocytosis in E. sinensis, providing mechanistic insight into integrin-mediated immune adaptation in crustaceans and highlighting a potential target for enhancing disease resistance in aquaculture.

Related Concept Videos

Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal01:22

Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal

Erythropoietin-producing hepatocellular carcinoma receptor (Eph) and its ligand, Eph receptor-interacting protein (Ephrin) were first discovered in the human carcinoma cell line, hence the name. Ephrin-Eph interaction guides cells to reach their appropriate location in adult tissues. They also play an essential role in the immune system by helping in immune cell migration, adhesion, and activation. Based on their structure and function, Eph is divided into two classes — EphA and EphB.
1.8K
Integrins01:10

Integrins

Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
4.8K
Activation of Integrins01:15

Activation of Integrins

Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
4.3K
Adherens Junctions01:24

Adherens Junctions

Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types –  adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as  epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as  heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
5.8K
Selectins01:25

Selectins

Cell adhesion is  an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain,...
3.6K
Anchoring Junctions01:03

Anchoring Junctions

Anchoring junctions are multiprotein complexes that help cells connect to other cells and the extracellular matrix. Anchoring junctions are present on the lateral and basal surfaces of cells, providing strong and flexible connections. Focal adhesions are often formed due to cell interactions with the ECM substrata, which initiate signal transduction via kinase cascades and other mechanisms. Together, they provide stability and tissue integrity. There are three types of anchoring junctions:...
4.2K