Analysis of intracellular and intraviral localization of the human cytomegalovirus UL53 protein.
Human cytomegalovirus (HCMV) UL53 belongs to a family of conserved herpesvirus genes. In this work, the expression and localization of the UL53 gene product was analysed. Results obtained showed that pUL53 is a new structural protein. In infected human fibroblasts, pUL53 localizes in cytoplasmic perinuclear granular formations together with other structural viral proteins. In the nucleus, pUL53 forms patches at the nuclear periphery and co-localizes with lamin B at the internal nuclear membrane level. Immunoelectron microscopy studies have disclosed that nuclear pseudo-inclusions are labelled, whereas nucleocapsid formations within the intranuclear skein are negative. Furthermore, the mature virus particle maintains pUL53 at its tegumental level. These data suggest that pUL53 could be involved either in nucleocapsid maturation or in the egress of nucleocapsids from the nucleus to the cytoplasm through the nuclear membrane, a role compatible with the function hypothesized for UL31, its positional homologue in herpes simplex virus type 1.
Dal Monte
P
P
Department of Clinical and Experimental Medicine, Division of Microbiology, University of Bologna, St Orsola General Hospital, Via Massarenti 9, 40138 Bologna, Italy1.
Pignatelli
S
S
Department of Clinical and Experimental Medicine, Division of Microbiology, University of Bologna, St Orsola General Hospital, Via Massarenti 9, 40138 Bologna, Italy1.
Zini
N
N
Institute of Normal and Pathologic Cytomorphology, CNR, c/o IOR, Bologna, Italy2.
Maraldi
N M
NM
Institute of Normal and Pathologic Cytomorphology, CNR, c/o IOR, Bologna, Italy2.
Perret
E
E
Unité d'Oncologie Virale, Institut Pasteur, Paris, France3.
Prevost
M C
MC
Unité d'Oncologie Virale, Institut Pasteur, Paris, France3.
Landini
M P
MP
Department of Clinical and Experimental Medicine, Division of Microbiology, University of Bologna, St Orsola General Hospital, Via Massarenti 9, 40138 Bologna, Italy1.
D003587:Cytomegalovirus / Q000737:chemistry*; D006801:Humans; D016253:Microscopy, Immunoelectron; D015678:Viral Structural Proteins / Q000032:analysis* / Q000502:physiology; D014771:Virion / Q000737:chemistry
D015678:Viral Structural Proteins