The <i>Drosophila</i> Bruton’s Tyrosine Kinase (Btk) Homolog Is Required for Adult Survival and Male Genital Formation

Baba, Kohtaro; Takeshita, Aya; Majima, Kei; Ueda, Ryo; Kondo, Shunzo; Juni, Naoto; Yamamoto, Daisuke

doi:10.1128/mcb.19.6.4405

Cited by 46 publications

(62 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Drosophila, there are two isoforms of Tec29 RNA. The longer form (type 2) is similar to the vertebrate Tec kinases and includes the PH domain, whereas the shorter type 1 isoform lacks the PH and part of the TH domain at its N terminus (Baba et al, 1999a). We observed that the longer isoform of Tec29 is expressed only in the nervous system, whereas the shorter isoform is expressed in the epidermis and at high levels in the salivary glands (Fig.…”

Section: Resultsmentioning

confidence: 64%

Tec29controls actin remodeling and endoreplication during invagination of theDrosophilaembryonic salivary glands

Chandrasekaran

Beckendorf

2005

Development

View full text Add to dashboard Cite

Epithelial invagination is necessary for formation of many tubular organs,one of which is the Drosophila embryonic salivary gland. We show that actin reorganization and control of endocycle entry are crucial for normal invagination of the salivary placodes. Embryos mutant for Tec29, the Drosophila Tec family tyrosine kinase, showed delayed invagination of the salivary placodes. This invagination delay was partly the result of an accumulation of G-actin in the salivary placodes, indicating that Tec29 is necessary for maintaining the equilibrium between G- and F-actin during invagination of the salivary placodes. Furthermore, normal invagination of the salivary placodes appears to require the proper timing of the endocycle in these cells; Tec29 must delay DNA endoreplication in the salivary placode cells until they have invaginated into the embryo. Taken together, these results show that Tec29 regulates both the actin cytoskeleton and the cell cycle to facilitate the morphogenesis of the embryonic salivary glands. We suggest that apical constriction of the actin cytoskeleton may provide a temporal cue ensuring that endoreplication does not begin until the cells have finished invagination.

show abstract

Section: Resultsmentioning

confidence: 64%

Tec29controls actin remodeling and endoreplication during invagination of theDrosophilaembryonic salivary glands

Chandrasekaran

Beckendorf

2005

Development

View full text Add to dashboard Cite

show abstract

“…tec29 k00206 was used as the tec29 allele as it eliminates the tec29 transcript, as assayed by in situ hybridization (Roulier et al, 1998). Baba et al (Baba et al, 1999) and Sinka et al (Sinka et al, 2002) report some tec29 activity in this mutant suggesting that it is a strong reduction-of-function allele. Other alleles used include scraps RS and scraps PQ (Schüpbach and Wieschaus, 1989), and Df(3R)tll-e to delete bnk (Schejter and Wieschaus, 1993b).…”

Section: Fly Strains and Geneticsmentioning

confidence: 99%

src64andtec29are required for microfilament contraction duringDrosophilacellularization

2004

View full text Add to dashboard Cite

Formation of the Drosophila cellular blastoderm involves both membrane invagination and cytoskeletal regulation. Mutations in src64and tec29 reveal a novel role for these genes in controlling contraction of the actin-myosin microfilament ring during this process. Although membrane invagination still proceeds in mutant embryos, its depth is not uniform, and basal closure of the cells does not occur during late cellularization. Double-mutant analysis between scraps, a mutation in anillin that eliminates microfilament rings, and bottleneck suggests that microfilaments can still contract even though they are not organized into rings. However, the failure of rings to contract in the src64 bottleneck double mutant suggests that src64 is required for microfilament ring contraction even in the absence of Bottleneck protein. Our results suggest that src64-dependent microfilament ring contraction is resisted by Bottleneck to create tension and coordinate membrane invagination during early cellularization. The absence of Bottleneck during late cellularization allows src64-dependent microfilament ring constriction to drive basal closure.

show abstract

“…These protein-protein interactions are proposed to be essential in modulating Btk and Etk/BMX activity. In addition, a protein tyrosine phosphatase, PTPD1, which was identified by a yeast two-hybrid screen using the Etk PH domain as a bait, is able to enhance STAT3 tyrosine phosphorylation in COS cells.2 However, based on the elegant genetic studies on Drosophila Btk homologue, Dsrc29A, it is of interest to note that the PH domain of Dsrc29A is dispensable for Drosophila copulation and survival (14).It has been shown that Etk is involved in the interleukin-6-dependent signal transduction cascade and its consequent neuroendocrine differentiation in prostate cells (1) and the Srcmediated cell transformation.3 Recently, Etk was reported to protect prostate carcinoma LNCaP cells against apoptosis in-* This work was supported in part by National Institutes of Health Research Grant RO1-DE10742 (to D. K. A.).…”

mentioning

confidence: 99%

“…2 However, based on the elegant genetic studies on Drosophila Btk homologue, Dsrc29A, it is of interest to note that the PH domain of Dsrc29A is dispensable for Drosophila copulation and survival (14).…”

mentioning

confidence: 99%

“…In addition, a protein tyrosine phosphatase, PTPD1, which was identified by a yeast two-hybrid screen using the Etk PH domain as a bait, is able to enhance STAT3 tyrosine phosphorylation in COS cells. 2 However, based on the elegant genetic studies on Drosophila Btk homologue, Dsrc29A, it is of interest to note that the PH domain of Dsrc29A is dispensable for Drosophila copulation and survival (14).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Kinase Activation of the Non-receptor Tyrosine Kinase Etk/BMX Alone Is Sufficient to Transactivate STAT-mediated Gene Expression in Salivary and Lung Epithelial Cells

Wen¹,

Lin²,

Shih³

et al. 1999

Journal of Biological Chemistry

View full text Add to dashboard Cite

Etk/BMX is a non-receptor protein tyrosine kinase that requires a functional phosphatidylinositol 3-kinase via the pleckstrin homology domain to be activated by cytokine. In the present study, a conditionally active form of Etk was constructed by fusing the hormonebinding domain of estrogen receptor (ER) to an amino terminus truncated form of Etk, PH⌬1-68Etk, to generate ⌬Etk:ER. In stably transfected Pa-4⌬Etk:ER cells, the activity of ⌬Etk:ER was stimulated within minutes by the treatment of ⌬Etk:ER stimulant, estradiol, and sustained for greater than 24 h. A robust induction in the phosphorylation of signal transducers and activators of transcription (STAT) proteins, including STAT1, STAT3, and STAT5, was accompanied with ⌬Etk:ER activation. Moreover, the conditionally activated Etk stimulated STAT1-and STAT5-dependent reporter activities by ϳ160-and ϳ15-fold, respectively, however, elicited only a modest STAT3-mediated reporter activation. Qualitatively comparable results were obtained in lung A549 cells, indicating that ⌬Etk:ER inducible system could function in an analogous fashion in different epithelial cells. Furthermore, we demonstrated that Etk activation alone augmented cyclin D1 promoter/enhancer activity via its STAT5 response element in both Pa-4⌬Etk:ER and A549 cells. Altogether, these findings support the notion that the activation of Etk kinase is sufficient to transactivate STAT-mediated gene expression. Hence, our inducible ⌬Etk:ER system represents a novel approach to investigate the biochemical events following Etk activation and to evaluate the contribution by kinase activation of Etk alone or in conjunction with other signaling pathway(s) to the ultimate biological responses.Epithelial and endothelial tyrosine kinase (Etk), 1 also known as BMX, is a non-receptor tyrosine kinase that contains a pleckstrin homology (PH) domain at its amino terminus followed by Src homology SH3 and SH2 domains, and a tyrosine kinase domain (1, 2) (Fig. 1). Interest in the function and regulation of Etk/BMX activity has been invigorated by the findings that this enzyme belongs to the Tec family of nonreceptor protein-tyrosine kinases including additional members of Btk, Itk, Tec, and Txk (reviewed in Ref.3). For example, Etk/BMX compensates for the lack of Btk activity in B-cell receptor signal transduction by reconstituting phospholipase C␥2-dependent responses in Btk-deficient DT40 cells (4). However, these activities may not be the primary in vivo function of Etk/BMX, since Etk/BMX is predominantly expressed in lung and prostate tissues, as well as in salivary epithelial, endothelial, and granulomonocytic cells (1, 2, and this report), but not in B-cells.The PH domain, located at the Etk amino terminus, is a protein module that has been found in many signal transduction proteins to mediate either protein-lipid or protein-protein interactions (5). Activation of PI 3-kinase is a prerequisite for Etk/BMX activation, presumably due to the direct interaction between the resultant lipid product and the Etk/BMX PH...

show abstract

The Drosophila Bruton’s Tyrosine Kinase (Btk) Homolog Is Required for Adult Survival and Male Genital Formation

Cited by 46 publications

References 50 publications

Tec29controls actin remodeling and endoreplication during invagination of theDrosophilaembryonic salivary glands

Tec29controls actin remodeling and endoreplication during invagination of theDrosophilaembryonic salivary glands

src64andtec29are required for microfilament contraction duringDrosophilacellularization

Kinase Activation of the Non-receptor Tyrosine Kinase Etk/BMX Alone Is Sufficient to Transactivate STAT-mediated Gene Expression in Salivary and Lung Epithelial Cells

Contact Info

Product

Resources

About