c-Src tyrosine kinase co-associates with and phosphorylates signal transducer and activator of transcription 5b which mediates the proliferation of normal human B lymphocytes.
Clin Exp Immunol
; 156(3): 419-27, 2009 Jun.
Article
in En
| MEDLINE
| ID: mdl-19438593
ABSTRACT
c-Src is the normal human cellular protein homologue of the viral oncogene v-src. c-Src activity was reported recently to increase in CD40-activated human B lymphocytes, suggesting its involvement in proliferation. To elucidate the exact role of c-Src in this process, we investigated the effects of c-Src over-expression on normal B lymphocyte growth. B lymphocytes purified from human peripheral blood were infected with Ad5/F35 vector encoding either a constitutively active c-Src (c-Src/dominant-positive) or a dominant-negative c-Src (c-Src/DN). Little variation of B lymphocytes expansion could be observed between control enhanced yellow fluorescent protein and c-Src/dominant-positive-infected cells. In contrast, over-expression of c-Src/DN results in a 40% inhibition of B lymphocyte expansion. These results suggest that DN c-Src may compete with endogenous c-Src, resulting in partial inhibition of a transcriptional pathway involved in B lymphocyte proliferation. We demonstrate further that c-Src can phosphorylate signal transducer and activator of transcription 5b (STAT5b) on tyrosine 699 and that c-Src and STAT5b co-associate during B lymphocyte proliferation. These results confirm an important role for c-Src in the expansion of normal human B lymphocytes in vitro, in which c-Src may regulate STAT5b in the intracellular signalling pathway important for the proliferation of normal human B lymphocytes.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
B-Lymphocytes
/
Src-Family Kinases
/
STAT5 Transcription Factor
Type of study:
Risk_factors_studies
Limits:
Humans
Language:
En
Journal:
Clin Exp Immunol
Year:
2009
Document type:
Article
Affiliation country:
Canada
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM