Coreceptor for class 3 semaphorins. Necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance in the developing nervous system. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin. The plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down-stream signaling events in the cytoplasm.

Involved as a receptor for mab-20/sema-2a in the formation or stabilization of cell-cell contacts at several stages of epithelial morphogenesis. In early embryonic development, required for proper ventral closure of the epidermis. During male tail morphogenesis, involved in precursor cell sorting and in the formation of distinct sensory rays ().

Also known as Plexin-A1 (Plex 1) (Plexin-1).
PLXNA1: Coreceptor for SEMA3A, SEMA3C, SEMA3F and SEMA6D. Necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance, invasive growth and cell migration. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin. The plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down- stream signaling events in the cytoplasm. Interacts directly with NRP1 and NRP2. Interacts with FARP2, RND1 and KDR/VEGFR2. Binding of SEMA3A leads to dissociation of FARP2. Detected in fetal brain, lung, liver and kidney. Belongs to the plexin family.

Protein type: Membrane protein, integral; Motility/polarity/chemotaxis; Receptor, misc.

Cellular Component: cytoplasm; integral to plasma membrane; membrane; nucleus

Molecular Function: protein binding; semaphorin receptor activity

Biological Process: branchiomotor neuron axon guidance; regulation of axon extension involved in axon guidance; regulation of smooth muscle cell migration

Also known as Plexin-A2 (Plex 2) (Plexin-2).
PLXNA2: Coreceptor for SEMA3A and SEMA6A. Necessary for signaling by SEMA6A and class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance, invasive growth and cell migration. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin. The plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down- stream signaling events in the cytoplasm. Homodimer. The PLXNA2 homodimer interacts with a SEMA6A homodimer, giving rise to a heterotetramer. Interacts directly with NRP1 and NRP2. Interacts with RND1. Detected in fetal brain. Belongs to the plexin family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral; Receptor, misc.

Cellular Component: integral to plasma membrane

Molecular Function: semaphorin receptor activity

Biological Process: branchiomotor neuron axon guidance; cell surface receptor linked signal transduction; centrosome localization; granule cell precursor tangential migration; limb bud formation; neural tube development; pharyngeal system development; regulation of axon extension involved in axon guidance; regulation of cell migration; somitogenesis

PLXNA3: Coreceptor for SEMA3A and SEMA3F. Necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance in the developing nervous system. Regulates the migration of sympathetic neurons, but not of neural crest precursors. Required for normal dendrite spine morphology in pyramidal neurons. May play a role in regulating semaphorin-mediated programmed cell death in the developing nervous system. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin. The plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down-stream signaling events in the cytoplasm. Interacts with CBFA2T3/MTG16. Belongs to the plexin family.

Protein type: Membrane protein, integral

Cellular Component: cell junction; integral to plasma membrane; intracellular membrane-bound organelle; nucleus; plasma membrane

Molecular Function: semaphorin receptor activity

Biological Process: axon guidance; branchiomotor neuron axon guidance; facial nerve structural organization; hippocampus development; negative chemotaxis; negative regulation of axon extension involved in axon guidance; positive regulation of cytoskeleton organization and biogenesis; pyramidal neuron development; regulation of cell migration; trigeminal nerve structural organization

PLXNA4: Coreceptor for SEMA3A. Necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance in the developing nervous system. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin. The plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down-stream signaling events in the cytoplasm. Interacts with NRP1 and NRP2. Belongs to the plexin family. 4 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: 7q32.3

Cellular Component: integral to plasma membrane; plasma membrane

Molecular Function: semaphorin receptor activity

Biological Process: branchiomotor neuron axon guidance; regulation of axon extension involved in axon guidance; regulation of cell migration

Involved in peripheral and central nervous system axon guidance. Acts as a receptor for Sema-2a and seems to transduce signal by suppressing Rac activity and enhancing Rho activity.

PLXNB1: Receptor for SEMA4D. Plays a role in RHOA activation and subsequent changes of the actin cytoskeleton. Plays a role in axon guidance, invasive growth and cell migration. Belongs to the plexin family. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral; Motility/polarity/chemotaxis; Receptor, misc.

Cellular Component: integral to plasma membrane

Molecular Function: GTPase activating protein binding; protein binding; semaphorin receptor activity

Biological Process: axon extension; negative regulation of cell adhesion; negative regulation of osteoblast proliferation; neurite morphogenesis; positive regulation of axonogenesis; positive regulation of GTPase activity; positive regulation of phosphoinositide 3-kinase cascade; regulation of cell migration; regulation of cell shape; regulation of cytoskeleton organization and biogenesis

PLXNB2: Cell surface receptor for SEMA4C, SEMA4D and SEMA4G that plays an important role in cell-cell signaling. Binding to class 4 semaphorins promotes downstream activation of RHOA and phosphorylation of ERBB2 at 'Tyr-1248'. Required for normal differentiation and migration of neuronal cells during brain corticogenesis and for normal embryonic brain development. Regulates the migration of cerebellar granule cells in the developing brain. Plays a role in RHOA activation and subsequent changes of the actin cytoskeleton. Plays a role in axon guidance, invasive growth and cell migration. May modulate the activity of RAC1 and CDC42. Down-regulates macrophage migration in wound- healing assays (in vitro). Belongs to the plexin family.

Protein type: Membrane protein, integral

Cellular Component: cell surface; integral to plasma membrane

Molecular Function: protein binding; semaphorin receptor activity

Biological Process: brain development; homophilic cell adhesion; negative regulation of cell adhesion; neural tube closure; neuroblast proliferation; positive regulation of axonogenesis; regulation of cell shape; regulation of GTPase activity; regulation of protein amino acid phosphorylation

PLXNB3: Receptor for SEMA5A that plays a role in axon guidance, invasive growth and cell migration. Stimulates neurite outgrowth and mediates Ca(2+)/Mg(2+)-dependent cell aggregation. In glioma cells, SEMA5A stimulation of PLXNB3 results in the disassembly of F-actin stress fibers, disruption of focal adhesions and cellular collapse as well as inhibition of cell migration and invasion through ARHGDIA-mediated inactivation of RAC1. Belongs to the plexin family.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: Xq28

Cellular Component: cell surface; integral to plasma membrane; plasma membrane

Molecular Function: protein binding; protein domain specific binding; semaphorin receptor activity

Biological Process: homophilic cell adhesion; negative regulation of cell adhesion; negative regulation of cell migration; positive chemotaxis; positive regulation of axonogenesis; positive regulation of endothelial cell proliferation; regulation of cell shape

Also known as Plexin-C1 (Virus-encoded semaphorin protein receptor) (CD antigen CD232).
PLXNC1: Receptor for SEMA7A, for smallpox semaphorin A39R, vaccinia virus semaphorin A39R and for herpesvirus Sema protein. Binding of semaphorins triggers cellular responses leading to the rearrangement of the cytoskeleton and to secretion of IL6 and IL8. Belongs to the plexin family.

Protein type: Cell adhesion; Membrane protein, integral; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 12q23.3

Cellular Component: integral to plasma membrane; membrane; plasma membrane

Molecular Function: protein binding; receptor binding; semaphorin receptor activity

Biological Process: branchiomotor neuron axon guidance; cell adhesion; regulation of axon extension involved in axon guidance; regulation of cell migration

PLXND1: Cell surface receptor for SEMA4A and for class 3 semaphorins, such as SEMA3A, SEMA3C and SEMA3E. Plays an important role in cell-cell signaling, and in regulating the migration of a wide spectrum of cell types. Regulates the migration of thymocytes in the medulla. Regulates endothelial cell migration. Plays an important role in ensuring the specificity of synapse formation. Required for normal development of the heart and vasculature. Mediates anti-angiogenic signaling in response to SEMA3E. Belongs to the plexin family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral; Receptor, misc.

Chromosomal Location of Human Ortholog: 3q22.1

Cellular Component: integral to plasma membrane; lamellipodium; plasma membrane

Molecular Function: protein binding; protein domain specific binding; semaphorin receptor activity

Biological Process: angiogenesis; branchiomotor neuron axon guidance; endothelial cell migration; regulation of angiogenesis; regulation of axon extension involved in axon guidance; regulation of cell migration; synaptogenesis