Hematopoietic cell‐specific lyn substrate (HCLS1 or HS1): A versatile actin‐binding protein in leukocytes

• Published in: Journal of leukocyte biology Vol. 105; no. 5; pp. 881 - 890
• Main Authors: Castro‐Ochoa, Karla F., Guerrero‐Fonseca, Idaira M., Schnoor, Michael
• Format: Journal Article
• Language: English
• Published: United States 01.05.2019
• Subjects: actin remodeling; Actin-Related Protein 2-3 Complex - genetics; Actin-Related Protein 2-3 Complex - immunology; Actins - genetics; Actins - immunology; Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - immunology; Animals; Arp2/3 complex; Bone Marrow Cells - immunology; Bone Marrow Cells - pathology; Cell Adhesion; Cell Lineage - genetics; Cell Lineage - immunology; Cell Movement; Cell Proliferation; cortactin; Cortactin - genetics; Cortactin - immunology; Gene Expression Regulation; Humans; inflammation; integrins; leukemia; Leukemia - genetics; Leukemia - immunology; Leukemia - pathology; Leukocytes - classification; Leukocytes - immunology; Leukocytes - pathology; migration; Phagocytosis; Protein Binding; Signal Transduction; src-Family Kinases - genetics; src-Family Kinases - immunology; Arp2/3 complex; leukemia; integrins; actin remodeling; inflammation; migration; cortactin
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/JLB.MR0618-212R

Leukocytes are constantly produced in the bone marrow and released into the circulation. Many different leukocyte subpopulations exist that exert distinct functions. Leukocytes are recruited to sites of inflammation and combat the cause of inflammation via many different effector functions. Virtually all of these processes depend on dynamic actin remodeling allowing leukocytes to adhere, migrate, phagocytose, and release granules. However, actin dynamics are not possible without actin‐binding proteins (ABP) that orchestrate the balance between actin polymerization, branching, and depolymerization. The homologue of the ubiquitous ABP cortactin in hematopoietic cells is hematopoietic cell‐specific lyn substrate‐1, often called hematopoietic cell‐specific protein‐1 (HCLS1 or HS1). HS1 has been reported in different leukocytes to regulate Arp2/3‐dependent migration. However, more evidence is emerging that HS1 functions go far beyond just being a direct actin modulator. For example, HS1 is important for the activation of GTPases and integrins, and mediates signaling downstream of many receptors including BCR, TCR, and CXCR4. In this review, we summarize current knowledge on HS1 functions and discuss them in a pathophysiologic context. Review of the cell functions of the actin‐binding protein HS1 that go far beyond actin remodeling.