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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The vertebrate gene
HCK
encodes a protein-tyrosine kinase that is closely related to the product of the proto-oncogene
SRC
.
HCK
is expressed principally in monocytic and granulocytic hematopoietic cells, in coordination with differentiation of these cells. Here we report an initial description of the mechanisms by which expression of human
HCK
is controlled. Induction of the gene during differentiation was manifested by an increase in the steady-state levels of
HCK
RNA and protein product. The accumulation of RNA apparently resulted from modulation of transcription itself, since no change occurred in the stability of the transcripts. Transcription initiated at multiple sites, clustered c. 145 nucleotides upstream of the first intron of
HCK
. The sequence of 660 bp upstream of the major initiation site was determined, revealing candidate binding sites for Sp1 and AP-2 transcription factors, but neither TATA nor CAAT elements. Comparison to the same region of the mouse hck locus showed five small regions of similarity, only two of which were topographically analogous between the two sequences. It appears that expression of
HCK
is regulated primarily through control of transcription, but the mechanisms by which tissue-specific expression and increase of transcription during differentiation are achieved remain to be explored.
...
PMID:Human protein-tyrosine kinase gene HCK: expression and structural analysis of the promoter region. 137 73
IL-2 is one of the principal growth factors regulating the proliferation of T lymphocytes. Although two independent IL-2-binding molecules have been molecularly cloned and shown to participate in the formation of a high affinity receptor complex, their primary structures do not suggest a specific mechanism for IL-2 growth signal transduction across the cell membrane. Neither IL-2 receptor subunit contains an intrinsic kinase domain; nevertheless, tyrosine phosphorylation of various intracellular substrates is one of the first biochemical changes observed following activation of the IL-2 receptor (IL-2R). Both serine/threonine and tyrosine kinases can be co-precipitated as part of the IL-2R complex suggesting that the IL-2 signalling may involve the activation of non-covalently associated intracellular kinases. However, controversy exists as to which kinases are involved in IL-2 signal transduction; in particular, which kinase(s) mediates the first or proximal event(s) in the signalling process. Activation of the IL-2R leads to serine and threonine phosphorylation of the
SRC
tyrosine kinase family member,
LCK
, and an increase in
LCK
tyrosine kinase activity. Furthermore,
LCK
can be co-immunoprecipitated with the beta chain of the IL-2R indicating its association with the receptor complex. IL-2 has also been reported to increase
FYN
kinase activity and to alter its association with the 85 kDa subunit of phosphatidylinositol-3 kinase thus suggesting a role for
FYN
in IL-2 signal transduction. However, in this report, we now demonstrate that neither
LCK
nor
FYN
are obligatory for IL-2-induced growth of HTLV-I-infected human T cells. Lack of expression of
LCK
or
FYN
in the HTLV-I-infected T cell lines was demonstrated by a combination of Northern blotting, polymerase chain reaction, Western blotting, and in vitro kinase activity. Despite the absence of
LCK
or
FYN
, IL-2 induced similar patterns of rapid tyrosine phosphorylation. Similar results were observed in cell lines lacking expression of the
LYN
,
FGR
,
HCK
, and LTK tyrosine kinases. Thus, none of these tyrosine kinases alone appears to be required for growth signalling through the IL-2R in the HTLV-I-infected T cell lines analyzed. The findings raise the possibility that an, as yet, unidentified tyrosine kinase is involved. Alternatively, this biological signalling system may exhibit remarkable redundancy whereby several different tyrosine kinases may be capable of associating with the IL-2R complex and mediating intracellular signalling.
...
PMID:Neither the LCK nor the FYN kinases are obligatory for IL-2-mediated signal transduction in HTLV-I-infected human T cells. 147 76
Protein tyrosine kinases (PTKs) are implicated in the control of cell growth by virtue of their frequent appearance as products of retroviral oncogenes, as intracellular signal transducers, and as growth factor receptors or components thereof. The knowledge of the structure and sequence of family genes encoding PTKs is still limited. To date, the complete genomic structure of human src family members is only available for the C-FGR gene (encoding p55 Fgr, PTK). Sequence analysis and characterization of the intron/exon organization of the human
HCK
gene, encoding a hemopoietic-specific cell PTK of the src-related family, revealed a length of over 16 kb for the seven 3'-exons. All intron/exon splice junctions agree with the GT/AG rule. In each case where a boundary occurs at a Gly codon, GGG or GGA, the triplet is split between the first and second nucleotide (nt). A total of eight complete and one partial Alu repeats were identified within the introns. The nt sequence of the genomic clones resolves existing discrepancies among two published sequences of
HCK
cDNAs. Human
HCK
, C-SRC (encoding p60 Src PTK), C-FGR and
LCK
(encoding p56 Lck, PTK) genes thus share very similar exon/intron structures for the conserved exons. These results provide additional evidence that the different PTKs of the src-like family most likely arose by duplication of an ancestral src-like gene.
...
PMID:The genomic locus of the human hemopoietic-specific cell protein tyrosine kinase (PTK)-encoding gene (HCK) confirms conservation of exon-intron structure among human PTKs of the src family. 157 49
Unlike many other growth factor receptors, the known subunits of the receptors for the Interleukins IL-2 and IL-3 lack intrinsic tyrosine kinase activity, and yet increases in the phosphorylation of proteins on tyrosines is a rapid event in hematolymphoid cells following stimulation with these lymphokines. Here we show that IL-2 and IL-3 regulate the activity of specific members of the
SRC
-family of non-receptor protein tyrosine kinases (PTKs). In IL-2-dependent T-cell lines, IL-2 induced rapid and transient increases in the activity of the p56-LCK kinase without influencing the activities of other
SRC
-like PTKs (p59-
FYN
, p62-YES) in these T-lymphocytes. In contrast to IL-2's effects on p56-LCK in T-cells, studies of an IL-2-responsive cell line of the B-cell lineage that lacks p56-LCK revealed that IL-2 specifically regulates the activity of the p53/56-
LYN
kinase. Thus, some flexibility exists in the ability of various
SRC
-like PTKs to functionally couple to IL-2 signalling pathways. In several IL-3-dependent myeloid-committed leukemic cell lines, IL-3 was found to specifically regulate the activity of the p53/56-
LYN
kinase without affecting the activities of other
SRC
-like PTKs (p59/64-
HCK
, p59-
FYN
, p62-YES) in these hematopoietic cells. This finding that p53/56-
LYN
can be regulated by both IL-2 in B-lineage cells and IL-3 in myeloid-committed cells demonstrates that the same
SRC
-family PTK can participate in signal transduction events mediated via two independent receptor systems. Taken together, our findings imply that the specific combinations of lymphokine receptors and
SRC
-like PTKs available for coupling with those receptors are coordinately controlled during the differentiation of hematopoietic cells.
...
PMID:Regulation of SRC-family protein tyrosine kinases by interleukins, IL-2, and IL-3. 160 36
The expression of protein-tyrosine kinases (PTKs; ATP:protein-tyrosine O-phosphotransferase, EC 2.7.1.112) was studied in normal human lung and various tumors by PCR followed by molecular cloning and sequence analysis. Six known PTKs (YES,
FGR
,
LYN
,
HCK
, PDGFB-R, and CSF1-R), as well as two additional members of this enzyme family, were detected in lung. One of the newly discovered sequences appears to represent a group of cytosolic PTKs. The cDNA sequence of the second unknown PTK revealed that it is a fourth member of the fibroblast growth factor receptor family. It was therefore called TKF (tyrosine kinase related to fibroblast growth factor receptor). Among a wide variety of cells and tissues tested, including human lymphocytes and macrophages, TKF was only found expressed in lung. Apart from normal lung, TKF expression could be demonstrated in some tumors of lung origin, but also in malignancies not derived from lung tissues. As fibroblast growth factors are generally involved in a variety of functions such as mitogenesis, angiogenesis, and wound healing, the specific expression of a receptor-related gene in lung only may point to yet another special function of this group of proteins.
...
PMID:Two additional protein-tyrosine kinases expressed in human lung: fourth member of the fibroblast growth factor receptor family and an intracellular protein-tyrosine kinase. 172 May 39
While examining a series of transgenic mouse lines carrying the
HCK
protooncogene, we encountered one line in which males hemizygous for the transgene were sterile. The sterile males mated normally but failed to impregnate females. Light and electron microscopy revealed that spermatogenesis proceeds normally until nuclear condensation, which occurs but gives rise to a variety of abnormally shaped nuclei. Expression of the transgene was not detectable. Thus, the insertion itself probably caused the abnormal phenotype by disrupting a gene (or genes) important in spermatogenesis. The mutation is genetically dominant, causing an abnormal phenotype even though the sterile mice carry an ostensibly normal counterpart of the disrupted locus. The mutant phenotype is completely penetrant only in some genetic backgrounds, suggesting a modifying influence from a second locus. Junctions between the inserted transgene and adjoining cellular DNA were cloned, allowing us to confirm the heterozygous nature of the genetic disruption and to detect and associated deletion. We have designated the mutation Lvs (lacking vigorous sperm) and presume that it may define a previously undescribed locus important in spermatogenesis.
...
PMID:Dominant male sterility in mice caused by insertion of a transgene. 194 51
The number of gene assignments to human chromosome 20 has increased slowly until recently. Only seven genes and one fragile site were confirmed assignments to chromosome 20 at the Ninth Human Gene Mapping Workshop in September 1987 (HGM9). One fragile site, 13 additional genes, and 10 DNA sequences that identify restriction fragment length polymorphisms (RFLPs), however, were provisionally added to the map at HGM9. Five mutated genes on chromosome 20 have a relation to disease: a mutation in the adenosine deaminase gene results in a deficiency of the enzyme and severe combined immune deficiency; mutations in the gene for the growth hormone releasing factor result in some forms of dwarfism; mutations in the closely linked genes for the hormones arginine vasopressin and oxytocin and their neurophysins are probably responsible for some diabetes insipidus; and mutations in the gene that regulates both alpha-neuraminidase and beta-galactosidase activities determine galactosialidosis. The gene for the prion protein is on chromosome 20; it is related to the infectious agent of kuru, Creutzfeld-Jacob disease, and Gertsmann-Straussler syndrome, although the nature of the relationship is not completely understood. Two genes that code for tyrosine kinases are on the chromosome, SRC1 the proto-oncogene and a gene (
HCK
) coding for haemopoietic kinase (an src-like kinase), but no direct relation to cancer has been shown for either of these kinases. The significance of non-random loss of chromosome 20 in the malignant diseases non-lymphocytic leukaemia and polycythaemia vera is not understood. Twenty-four additional loci are assigned to the chromosome: five genes that code for binding proteins, one for a light chain of ferritin, genes for three enzymes (inosine triphosphatase, s-adenosylhomocysteine hydrolase, and sterol delta 24-reductase), one for each of a secretory protein and an opiate neuropeptide, a cell surface antigen, two fragile sites, and 10 DNA sequences (one satellite and nine unique) that detect RFLPs.
...
PMID:The map of chromosome 20. 307 44
We have isolated cDNAs representing a previously unrecognized human gene that apparently encodes a protein-tyrosine kinase. We have designated the gene as
HCK
(hemopoietic cell kinase) because its expression is prominent in the lymphoid and myeloid lineages of hemopoiesis. Expression in granulocytic and monocytic leukemia cells increases after the cells have been induced to differentiate. The 57-kilodalton protein encoded by
HCK
resembles the product of the proto-oncogene c-src and is therefore likely to be a peripheral membrane protein.
HCK
is located on human chromosome 20 at bands q11-12, a region that is affected by interstitial deletions in some acute myeloid leukemias and myeloproliferative disorders. Our findings add to the diversity of protein-tyrosine kinases that may serve specialized functions in hemopoietic cells, and they raise the possibility that damage to
HCK
may contribute to the pathogenesis of some human leukemias.
...
PMID:Identification of a human gene (HCK) that encodes a protein-tyrosine kinase and is expressed in hemopoietic cells. 349 23
The expression patterns of low and high molecular weight cytokeratins (
LCK
and
HCK
) vimentin and desmin were investigated by immunocytochemistry in the rete testis and epididymis in the dog. The epithelium of the rete testis displayed coexpression of
LCK
, vimentin and desmin. The epithelium of the efferent ductules was composed of ciliated and nonciliated cells; the ciliated cells expressed
LCK
strongly. The epithelium of the epididymal duct was composed of principal, apical and basal cells. Principal cells in the duct of the head of the epididymis displayed
LCK
and vimentin, with a predominance of
LCK
in the apical cytoplasmic regions and vimentin in the basal portions of the cells. Expression of vimentin in the principal cells decreased towards the body of the epididymis and disappeared in the tail region, where
LCK
remained unchanged. Apical cells of the epididymal duct expressed
LCK
. Basal cells in the duct of the head and body of the epididymis showed
LCK
and those of the duct of the body of the epididymis also
HCK
expression.
...
PMID:Coexpression of different cytokeratins, vimentin and desmin in the rete testis and epididymis in the dog. 751 42
Deletions of the long arm of chromosome 20 [del(20q)] are recurring abnormalities in patients with myeloid disorders. Although variable in size, these deletions are usually interstitial. With the object of defining a commonly deleted region for smaller 20q deletions, we used quantitative Southern blot analysis complemented by restriction fragment length polymorphism (RFLP) analysis to determine the copy number at 15 loci spanning 20q. The proximal breakpoints of three such deletions were found to separate
HCK
and the growth hormone releasing factor (GHRF) locus near the centromeric boundary of band 20q11.2. The distal breakpoints were localized to the vicinity of the D20S22 locus in band q13.1. A candidate tumor suppressor gene, RBL2, and the
SRC
oncogene were both located within the commonly deleted region. Six loci in terminal region q13.2-q13.3 were conserved on these del(20q) chromosomes, thereby confirming that the deletions were interstitial. Molecular heterogeneity at one and possibly both deletion breakpoints rules out the pathological involvement of loci at these sites. Instead, loss of a tumor suppressor locus from within the commonly deleted region may contribute to deregulated hemopoiesis.
...
PMID:Molecular heterogeneity at the breakpoints of smaller 20q deletions. 752 43
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