High impact information on VPREB3

• The pre-B lymphocyte protein 3 (VPREB3) is expressed during B cell differentiation and in subsets of mature B lymphocytes and is mainly found in bone marrow and lymphoid tissue germinative centers [1].
• So far, the function of VPREB3 in B lymphocytes remains to be clarified [1].
• The human VPREB3 shows a B cell-specific expression in hematopoietic cell lines [2].
• Besides the bone marrow, the VPREB3 protein is also expressed in secondary lymphoid organs, such as the tonsils [3].
• It has been discussed whether VPREB3 can help the transport of the mu chains within the cytoplasm and/or assembly the pre-BCR prior to membrane expression [2] [3].
• Nevertheless, the precise functions of VPREB3 remain unknown and it has been reasonably questioned whether it can have functions beyond early B lymphocyte development [3].
• VPREB3 was previously identified at the RNA level in aldosterone-producing adenomas of the adrenal cortex, as well as in non-tumoral adrenal cortex samples adjacent to those adenomas [4]. However, those authors did not address the expression of VPREB3 at the protein level, as well as it's exact localization in human adrenocortical tissues [4].
• It is now known that VPREB3 is present in the zona glomerulosa of the normal and hyperplastic adrenal cortex at the protein level [1].
• In patients with aldosterone-producing adenoma, the mRNA levels of VPREB3 positively and significantly correlate to those of plasma aldosterone, while showing no correlation to the levels of plasma cortisol  [1].
• The mRNA levels of VPREB3 also positively and significantly correlate to those of several other genes implicated in aldosterone biosynthesis, such as CYP11B2, HSD3B2, PCP4, CACNA1D and CACNA1H  [1].
• The VPREB3 protein has been detected in Purkinje neurons of the human cerebellum  [1].
• Despite not providing those cells with similar functions due to obvious differences in specialization, the sharing of VPREB3 and other functionally relevant proteins (e.g. glutamate receptors) among the Purkinje cells of the cerebellum, the aldosterone-producing cells of the adrenal and lymphocytes might well suggest a common stem cell ancestor during embryogenesis [1].
• Previous studies show that VPREB3 can be detected in several human cell lines representative of all stages of B-lymphocyte differentiation [3].

References