| General Information |
| MoonProt ID | 133 |
| First appeared in release | 1.0 |
| Name(s) | Thymosin beta-4
T beta-4
TB4X
THYB4
TMSB4
Gene Name: TMSB4X
|
| UniProt ID | P62328 (TYB4_HUMAN), Reviewed |
| GO terms | GO:0002576 platelet degranulation
GO:0007010 cytoskeleton organization
GO:0007596 blood coagulation
GO:0030036 actin cytoskeleton organization
GO:0030168 platelet activation
GO:0042989 sequestering of actin monomers
GO:0003779 actin binding
GO:0005515 protein binding
GO:0044822 poly(A) RNA binding
GO:0005576 extracellular region
GO:0005737 cytoplasm
GO:0005856 cytoskeleton
GO:0031093 platelet alpha granule lumen |
| Organisms for which functions have been demonstrated | Homo sapiens (human, a mammal) and Bos taurus (cow, a mammal) |
| Sequence length | 44 |
| FASTA sequence | >gi|11056061|ref|NP_066932.1| thymosin beta-4 [Homo sapiens]
MSDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES |
| Structure Information |
| PDB ID | 4PL8_H |
| Quaternary structure | |
| SCOP | NA |
| CATH | NA |
| TM Helix Prediction | no TM helices |
| DisProt Annotation | 100% disordered |
| Predicted Disorder Regions | 1-12, 20-44 |
| Connections to Disease |
| OMIM ID | |
| Function 1 |
| Function description | Involved in sequestering G-actin (monomeric actin) in human polymorphonuclear leukocytes (PMNs).
|
| References for function | D Safer, M Elzinga, and V T Nachmias. Thymosin beta 4 and Fx, an actin-sequestering peptide, are indistinguishable. J. Biol. Chem. 1991 266: 4029-32.
Cassimeris, L., Safer, D., Nachmias, V.T. & Zigmond, S.H. Thymosin ?4 sequesters the majority of G-actin in resting human polymorphonuclear leukocytes. J. Cell Biol. 119, 12611270 (1992). |
| E.C. number | N/A |
| Location of functional site(s) | |
| Cellular location of function | cytoplasm |
| Comments | "Thymosin B4 appears to be an intrinsically disordered protein that binds to actin. Modeling and Cross-linking studies suggest that TB4 binds to actin at locations: Lys3, Lys18, Lys38. However, a high percentage of residues still do participate in functional interactions between the two macromolecules."
From: Safer, D. et al . 1997. Thymosin beta 4 binds actin in an extended conformation and contacts both the barbed and pointed ends. Biochemistry 36: 58065816.
Thymosin B4 forms a 1:1 complex with G-actin and inhibits its polymerization. PDB #1T44 contains a fragment of Thymosin B4. |
| Function 2 |
| Function description | secreted anti-inflammatory agent |
| References for function | Young JD, Lawrence AJ, MacLean AG, Leung BP, McInnes IB, Canas B, Pappin DJ, Stevenson RD. Thymosin beta 4 sulfoxide is an anti-inflammatory agent generated by monocytes in the presence of glucocorticoids. Nat Med. 1999 Dec. PMID: 10581087 |
| E.C. number | N/A |
| Location of functional site(s) | |
| Cellular location of function | Extracellular. Secreted protein. |
| Comments | "Met-6 is thought to play an important role in the signaling process."
Young JD, Lawrence AJ, MacLean AG, Leung BP, McInnes IB, Canas B, Pappin DJ, Stevenson RD. Nat Med. 1999 Dec;5(12):1424-7. PMID: 10581087
"Thymosin B4 is generated by monocytes in the presence of glococorticoids and inhibits anti-inflammatory response. Thymosin B4 sulfoxide is formed by the oxidation of Methionine 6 (Met-6), and appears to be the active form in inhibiting inflammation." |