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- ***********************************************
- * Heat shock hsp70 proteins family signatures *
- ***********************************************
-
- Prokaryotic and eukaryotic organisms respond to heat shock or other
- environmental stress by the induction of the synthesis of proteins
- collectively known as heat-shock proteins (hsp) [1]. Amongst them is a family
- of proteins with an average molecular weight of 70 Kd, known as the hsp70
- proteins [2,3,4]. In most species, there are many proteins that belong to the
- hsp70 family. Some of them are expressed under unstressed conditions. Hsp70
- proteins can be found in different cellular compartments (nuclear, cytosolic,
- mitochondrial, endoplasmic reticulum, etc.). Some of the hsp70 family proteins
- are listed below:
-
- - In Escherichia coli and other bacteria, the main hsp70 protein is known as
- the dnaK protein. A second protein, hscA, has been recently discovered.
- dnaK is also found in the chloroplast genome of red algae.
- - In yeast, at least ten hsp70 proteins are known to exist: SSA1 to SSA4,
- SSB1, SSB2, SSC1, SSD1 (KAR2), SSE1 (MSI3) and SSE2.
- - In Drosophila, there are at least eight different hsp70 proteins: HSP70,
- HSP68, and HSC-1 to HSC-6.
- - In mammals, there are at least eight different proteins: HSPA1 to HSPA6,
- HSC70, and GRP78 (also known as the immunoglobulin heavy chain binding
- protein (BiP)).
- - In the sugar beet yellow virus (SBYV), a hsp70 homolog has been shown [5]
- to exist.
- - In archebacteria, hsp70 proteins are also present [6].
-
- All proteins belonging to the hsp70 family bind ATP. A variety of functions
- has been postulated for hsp70 proteins. It now appears [7] that some hsp70
- proteins play an important role in the transport of proteins across membranes.
- They also seem to be involved in protein folding and in the assembly/
- disassembly of protein complexes [8].
-
- We have derived three signature patterns for the hsp70 family of proteins; the
- first centered on a conserved pentapeptide found in the N-terminal section of
- these proteins; the two others on conserved regions located in the central
- part of the sequence.
-
- -Consensus pattern: [IV]-D-L-G-T-T-x-S
- -Sequences known to belong to this class detected by the pattern: ALL, except
- for 8 divergent members of the family.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: [LIVMF]-[LIVMFY]-D-[LIVMF]-G-[GSH]-[GS]-[AST]-x(3)-[ST]-
- [LIVM]-[LIVMFC]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: [LIVM]-x-[LIVM]-x-G-G-x-[ST]-x-[LIVM]-P-x-[LIVM]-x-
- [DEQKRSTA]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: Physarum polycephalum actin D.
-
- -Last update: June 1994 / Patterns and text revised.
-
- [ 1] Lindquist S., Craig E.A.
- Annu. Rev. Genet. 22:631-677(1988).
- [ 2] Pelham H.R.B.
- Cell 46:959-961(1986).
- [ 3] Pelham H.R.B.
- Nature 332:776-77(1988).
- [ 4] Craig E.A.
- BioEssays 11:48-52(1989).
- [ 5] Agranovsky A.A., Boyko V.P., Karasev A.V., Koonin E.V., Dolja V.V.
- J. Mol. Biol. 217:603-610(1991).
- [ 6] Gupta R.S., Singh B.
- J. Bacteriol. 174:4594-4605(1992).
- [ 7] Deshaies R.J., Koch B.D., Schekmam R.
- Trends Biochem. Sci. 13:384-388(1988).
- [ 8] Craig E.A., Gross C.A.
- Trends Biochem. Sci. 16:135-140(1991).
-