Rotavirus A Outer capsid protein VP4 (VP4)

Rotavirus A Outer capsid protein VP4 is a critical structural component of the rotavirus virion, forming the spikes that protrude from the outer shell. It is a protease-sensitive protein that must be cleaved by trypsin-like enzymes into two subunits, VP8* and VP5*, to become fully infectious. The VP8* subunit forms the distal head of the spike and is responsible for the initial attachment of the virus to host cell receptors, such as sialic acids or histo-blood group antigens (HBGAs), depending on the viral genotype. This interaction is a primary determinant of host range and tissue tropism. VP4 is also a major target for neutralizing antibodies, making it a key focus for vaccine development and therapeutic intervention. Mutations in the VP8* domain can lead to the emergence of new strains that escape host immunity or adapt to different host populations. The protein's role in cell penetration is primarily mediated by the VP5* subunit, which facilitates membrane permeabilization after attachment. Understanding the structural and functional diversity of VP4 is essential for monitoring vaccine efficacy and the evolution of rotavirus strains globally.

Other names

VP8*VP5*HemagglutininSpike proteinRotavirus A VP4/VP8*Outer capsid protein VP4

Neutralization of viral infectivity by blocking initial attachment to host cell glycans (VP8*) or preventing membrane penetration (VP5*).