Transcript levels of thymosin beta 4, an actin-sequestering peptide, in cell proliferation.
Thymosin beta 4 (beta 4) is an ubiquitous 5-kDa peptide that has been identified as an actin-sequestering peptide. In this work, Northern blot analysis was used to study the beta 4 mRNA levels during the cell cycle of rat thymocytes and hepatocytes as well as in human lymphocytes from patients with leukemia. beta 4 mRNA was found in all the stages of thymocyte and hepatocyte cell cycle, showing an increase in the S-phase which was maintained during the G2 and M phases. Incubation of splenic T-cells with concanavalin A, phorbol myristate acetate or the ionophore A23187 lead to a similar increase of beta 4 transcript during the S-phase. The increase in beta 4 mRNA observed in the G2/M boundary of the cell cycle, together with its ability to inhibit actin polymerization, suggests a possible role of beta 4 in the the morphological changes and actin redistribution occurring during the cytokinesis.
Otero
A
A
Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago, Santiago de Compostela, La Coruña, Spain.
Bustelo
X R
XR
Pichel
J G
JG
Freire
M
M
Gómez-Márquez
J
J
D000199:Actins / Q000737:chemistry*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002455:Cell Division / Q000235:genetics*; D003208:Concanavalin A / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007938:Leukemia / Q000235:genetics; D008099:Liver / Q000378:metabolism; D008115:Liver Regeneration; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D010455:Peptides / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013947:Thymosin / Q000737:chemistry / Q000235:genetics*; D013950:Thymus Gland / Q000378:metabolism; D013997:Time Factors; D000099201:Thymosin beta(4)
D000199:Actins; D000001:Calcimycin; D003208:Concanavalin A; D010455:Peptides; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; D013947:Thymosin; D000099201:Thymosin beta(4)