The @entity8315 is responsible for the central nervous system (CNS) @entity17 observed in cases of @entity7578 ( @entity7578 ). @entity281 of oligodendrocytes, the cells that constitute the basis of myelin in the CNS, is established by JCV in conjunction with immunosuppressive conditions. Beyond this, however, many questions related to JCV pathogenesis remain unanswered. The JCV regulatory region is a hypervariable noncoding sequence positioned between the early and late protein-coding regions. The particular @entity377 sequence of a JCV regulatory region affects levels of viral transcription and replication. Modifications to this promoter/enhancer structure can alter the cellular host range and may be responsible for switching JCV between states of lytic and @entity281 . The regulatory region structure has, therefore, been used to distinguish JCV variants. @entity377 sequencing studies have uncovered numerous variations of regulatory region structure. Until now, however, no inclusive nomenclature existed that linked variants by regulatory region structure and/or activity. We have arranged all known variant JCV regulatory regions into quadrants according to the integration of particular sequence sections and repetition of sequence section groups. This arrangement of regulatory regions results in an updated nomenclature that is well-suited for describing the relationships between JCV variants. Four distinct structural forms (I-S, I-R, II-S, and II-R) are defined along with tissue tropisms. This design provides logical connections between the variant regulatory regions and may be useful for elucidating crucial steps in JCV pathogenesis.

A classification scheme for @entity8315 variants based on the XXXX sequence of the noncoding regulatory region.

@entity17 :: ('MESH:D003711', 'Disease') :: ['demyelination'] @entity8315 :: ('10632', 'Species') :: ['human polyomavirus JCV'] @entity377 :: ('CHEBI:36976', 'Chemical') :: ['nucleotide', 'Nucleotide'] @entity281 :: ('MESH:D007239', 'Disease') :: ['Lytic infection', 'latent infection'] @entity7578 :: ('MESH:D007968', 'Disease') :: ['progressive multifocal leukoencephalopathy', 'PML']
@entity377 :: (CHEBI:36976,Chemical) :: ['nucleotide']
