The Spleen Protein‐Tyrosine Kinase TPK‐IIB is Highly Similar to the Catalytic Domain of p7P<sup>syk</sup>

Brunati, Anna Maria; James, Peter; Guerra, Bárbara; Ruzzene, Maria; Donella‐Deana, Arianna; Pinna, Lorenzo A.

doi:10.1111/j.1432-1033.1996.0400h.x

Cited by 28 publications

(23 citation statements)

References 23 publications

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“…These data are in good agreement with the high phosphorylation efficiency of the very hydrophobic mT-derived peptide substrate 15. In contrast, tyrosine kinase TPKIIB/p38"', strictly related to the catalytic domain of p72"' [38], selects glutamic acid at all positions between -4 and +2 (Table 5 ) , confirming also with the peptide library the acidophylic nature already outlined by using conventional peptide substrates [39, 401.…”

Section: Resultsmentioning

confidence: 59%

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Ruzzene

Songyang

Marin

et al. 1997

European Journal of Biochemistry

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An eicosapeptide encompassing the C-terminal tail of c-Src (Tyr527) which is conserved in most Srcrelated protein kinases, is phosphorylated by C-terminal Src kinase (CSK) and by the two Src-related protein kinases c-Fgr and Lyn, with similar kinetic constants. Two related peptides reproducing the Cterminal segments of c-Src mutants defective in CSK phosphorylation [MacAuley, A., Okada, M., Nada, S., Nakagawa, H. & Cooper, J. A. (1993) Oncogene 8,117-1241 AFLEDSCTGTEPLYQBGENL (mutant number 28) and AFLEDIJITGTKPQYHPGENL (mutant number 29), proved a better and a much worse substrates, respectively than the wild-type peptide, with either CSK or the two Src kinases. By changing individual residues in the best peptide substrate, it was shown that the main element responsible for its improved phosphorylation is leucine at position -1 (instead of glutamine), while lysine at position -3 (instead of glutamate) has a detrimental effect, possibly accounting for the negligible phosphorylation of peptide derived from mutant number 29. By contrast to most peptide substrates, including the Src C-terminal peptides, which exhibit relatively high K,, values, a polyoma-virus-middle-T-antigen-(mT)-derived peptide with tyrosine embedded in a highly hydrophobic sequence (EEEPQFEEIPIYLELLP) exhibits with CSK a quite low K, value (63 pM). Consistent with this, the optimal sequence selected by CSK in an oriented peptide library is XXXIYMFFF. This is different from sequences selected by Lyn (DEEIYEELX) and c-Fgr (XEEIYGIFF), although they all share a high selection for a hydrophobic residue at n-1. In sharp contrast, T P K I I B I P~~"~, related to the catalytic domain of p72'kk, selects acidic residues at nearly all positions, n-1 included.These data support the notion that the features determining the specific phosphorylation of the Cterminal tyrosine residue of Src do not reside in the primary structure surrounding the target tyrosine. They also show that this site does not entirely fulfil the optimal consensus sequence recognized by CSK, disclosing the possibility that as yet unrecognized CSK targets structurally unrelated to the C-terminal tyrosine residue of Src kinases may exist.Keywords: protein-tyrosine kinase; C-terminal Src kinase ; c-Fgr ; Lyn; specificity.The C-terminal Src kinase (CSK) is a cytoplasmic protein tyrosine kinase which specifically phosphorylates Src-family kinases at their C-terminal tyrosine residue (equivalent to Tyr527 in c-Src), which is a down-regulation site [I, 21. CSK is, therefore, responsible for inhibiting the Tyr kinase activity of members of the Src family by inducing a locked conformation that results from the intramolecular interaction between the C-terminal tyrosine residue phosphorylated by CSK and the Src homology 2 (SH2) domain of the Src kinase 13-61, CSK is expressed in most tissues, while a related kinase with high sequence similarity, recently cloned with different names, megacaryocyte-associated tyrosine kinase (MATK), Ntk, Ctk, Batk, Lsk and HYL, [7 -121 displays a more restricted exp...

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Section: Resultsmentioning

confidence: 59%

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Ruzzene

Songyang

Marin

et al. 1997

European Journal of Biochemistry

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“…It is conceivable that, given the high structural homology between p72 syk and ZAP-70, also the IA of the former is subjected to structural constraints by the C-terminal moiety of the molecule. Interestingly, Brunati et al (36) found that the catalytic domain of rat p72…”

Section: Discussionmentioning

confidence: 99%

Anti-peptide Antibodies Detect Conformational Changes of the Inter-SH2 Domain of ZAP-70 Due to Binding to the ζ Chain and to Intramolecular Interactions

Grazioli¹,

Germain²,

Weiss³

et al. 1998

Journal of Biological Chemistry

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T cell receptor (TCR) triggering induces association of the protein tyrosine kinase ZAP-70, via its two src-homology 2 (SH2) domains, to di-phosphorylated Immunoreceptor Tyrosine-based Activation Motifs (2pY-ITAMs) present in the intracellular tail of the TCR-chain. The crystal structure of the SH2 domains complexed with a 2pY-ITAM peptide suggests that the 60-amino acid-long inter-SH2 spacer helps the SH2 domains to interact with each other to create the binding site for the 2pY-ITAM. To investigate whether the inter-SH2 spacer has additional roles in the whole ZAP-70, we raised antibodies against two peptides of this region and probed ZAP-70 structure under various conditions. We show that the reactivity of antibodies directed at both sequences was dramatically augmented toward the tandem SH2 domains alone compared with that of the entire ZAP-70. This indicates that the conformation of the inter-SH2 spacer is not maintained autonomously but is controlled by sequences C-terminal to the SH2 domains, namely, the linker region and/or the kinase domain. Moreover, antibody binding to the same two determinants was also inhibited when ZAP-70 or the SH2 domains bound to the chain or to a 2pY-ITAM. Together, these two observations suggest a model in which intramolecular contacts keep ZAP-70 in a closed configuration with the two SH2 domains near to each other.ZAP-70 is a protein tyrosine kinase (PTK) 1 essential for the initiation of the signaling cascade activated by T cell antigen receptor triggering (1). Overall, ZAP-70 displays two structurally and functionally distinct moieties, an N-terminal one composed of two SH2 domains and a C-terminal kinase domain tethered by an ϳ80-amino acid-long linker (2) (also referred to as Interdomain B, (IB); Ref. 3).So far, the only known function of the region comprising the two SH2 domains (hereafter indicated as (SH2) 2 ) is to provide a means to recruit ZAP-70 to the plasma membrane by those TCRs engaged with the ligand (4, 5). This is achieved through the coordinated anchorage of the SH2 domains to di-phosphorylated tyrosine-containing motifs (D/E)XXYXX(I/L)X 6 -8 YXX (I/L) called ITAMs (for Immunoreceptor Tyrosine-based Activation Motifs) present within the cytoplasmic tails of TCR subunits and ⑀ (6 -8). Thereafter, ZAP-70 undergoes tyrosine phosphorylation culminating in the up-regulation of its catalytic activity which in turn is required for phosphorylating cellular substrates (9 -12).The x-ray crystal structure of the (SH2) 2 of human ZAP-70 complexed with a di-phosphorylated ITAM (2pY-ITAM) peptide (3) has revealed an unsuspected structural complementarity and immediate contiguity of the two SH2 domains needed to create a high affinity binding site for the 2pY-ITAM. Thus, while the C-terminal SH2 possesses a binding pocket for the first pY of the ITAM, the corresponding pocket for the second pY in the N-terminal SH2 is contributed, in part, by residues of the C-terminal SH2. Moreover, the 60 amino acids forming the inter-SH2 spacer (hereafter referred to as Interdomain ...

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“…Syk from rat spleen [22], Golgi apparatus CK from rat mammary gland [23]. Protein kinase (PK)A was from Sigma and PKC was from Boehringer Mannheim.…”

Section: A T E R I a L S A N D M E T H O D Smentioning

confidence: 99%

Ser/Thr phosphorylation of hematopoietic specific protein 1 (HS1). Implication of protein kinase CK2

Ruzzene¹,

Brunati²,

Sarno³

et al. 2000

Eur J Biochem

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Hematopoietic lineage cell-specific protein 1 (HS1), a tyrosine multiphosphorylated protein implicated in receptor-mediated apoptosis and proliferative responses, is shown here to become Ser/ Thr phosphorylated upon incubation of platelets with radiolabeled inorganic phosphate. The in vivo Ser/ Thr phosphorylation of HS1 is enhanced by okadaic acid and reduced by specific inhibitors of casein kinase (CK)2. In vitro, HS1 is an excellent substrate for either CK2 a subunit alone (K m 47 nm) or CK2 holoenzyme, tested in the presence of polylysine (K m 400 nm). Phosphorylation reaches a stoichiometry of about 2 mol phosphate per mol HS1 and occurs mainly at threonyl residue(s), mostly located in the N-terminal region, but also at seryl residue(s) residing in the central core of the molecule (208±402), as judged from experiments with deleted forms of HS1.Ser/ Thr phosphorylation of HS1, either induced in vivo by okadaic acid or catalysed in vitro by CK2, potentiates subsequent phosphorylation at tyrosyl residues. These data indicate the possibility that regulation of HS1 may also be under the control of Ser/ Thr phosphorylation, and suggest that in quiescent cells CK2 could play a role in inducing constitutive Tyr phosphorylation of HS1 in the absence of stimuli that activate the protein tyrosine kinase pathway.Keywords: HS1; CK2; casein kinase 2; phosphorylation; tyrosine kinase.HS1 is an intracellular protein whose expression is limited to hematopoietic and lymphoid cells [1]. Despite the fact that it is composed of 486 amino acids and has a predicted M r of about 54 000, HS1 is isolated as a protein of about 75 kDa as judged from SDS/PAGE. We have recently shown that this discrepancy is not due to post-translational modifications (e.g. glycosylation) but rather to its highly asymmetric rod shaped structure conferred by its central proline-rich domain [2]. The aminoacid sequence of HS1 contains a variety of structurally significant motifs, including: an N-terminal region responsible for the binding of mitochondrial protein HAX-1 [3], followed by four 37 amino-acid repeats that can form a helix-turn-helix structure frequently found in the DNA binding domain of various transcription factors [1]; a proline-rich region located at the C-terminus of the central moiety and ending with a stretch of proline-glutamate repeats; and an SH3 domain located at the C-terminal extremity.HS1 is readily tyrosine phosphorylated upon B-cell receptor cross-linking, in parallel with the activation of Src family kinases [4,5]. In vitro studies however, have revealed that HS1 is not a substrate for the Src-related kinases c-Fgr, Lyn and Fyn unless it has been phosphorylated previously by the protein tyrosine kinase Syk (not related to Src) [6,7]. Syk-mediated phosphorylation affects tyrosyl residues located just upstream from the SH3 domain domain (notably Tyr378 and Try397) and generates high-affinity binding sites for Src family SH2 domains. This provides the structural basis for subsequent association to and secondary phosphorylation by ...

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The Spleen Protein‐Tyrosine Kinase TPK‐IIB is Highly Similar to the Catalytic Domain of p7P^syk

Cited by 28 publications

References 23 publications

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Anti-peptide Antibodies Detect Conformational Changes of the Inter-SH2 Domain of ZAP-70 Due to Binding to the ζ Chain and to Intramolecular Interactions

Ser/Thr phosphorylation of hematopoietic specific protein 1 (HS1). Implication of protein kinase CK2

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The Spleen Protein‐Tyrosine Kinase TPK‐IIB is Highly Similar to the Catalytic Domain of p7Psyk

Cited by 28 publications

References 23 publications

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Sequence Specificity of C‐Terminal Src Kinase (Csk)

Anti-peptide Antibodies Detect Conformational Changes of the Inter-SH2 Domain of ZAP-70 Due to Binding to the ζ Chain and to Intramolecular Interactions

Ser/Thr phosphorylation of hematopoietic specific protein 1 (HS1). Implication of protein kinase CK2

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The Spleen Protein‐Tyrosine Kinase TPK‐IIB is Highly Similar to the Catalytic Domain of p7P^syk