regulation of polarized membrane transport by rab GTPases Peter van der Sluijs;

Transcription

1 regulation of polarized membrane transport by rab GTPases Peter van der Sluijs;

2 cytotoxic T cell recognizes complex of viral peptide with MHC class I and kills infected cell CTL infected cell janeway et al, 2005

3 if this does not work: hemophagocytic syndrome macrophage with ingested platelets and a lymphocyte

4 time course and modalities of T cell secretory responses today: CTL huse et al, 2008

5 proteins linked to MTOC polarization and release of lytic granules and cytokines Early TCR signaling: Src kinases, Zap70, Lat, SLP-76, Vav and PLC-gamma MTOC polarization: ADAP, Dynein, FMNL1, Dia1, IQGAP, Rac, Cdc42, Pyk2, Erk, HDAC6 Lytic-granule release: Rab27a, AP-3, Munc13-4, Syntaxin-11, Slp1, Slp2, Paxillin, PKCdelta, WIP Synaptic cytokine secretion: Rab3d, Rab19, Syntaxin-4, SNAP23, WASP Multidirectional cytokine secretion: Syntaxin-6 huse et al, 2008

6 transient adhesive interactions between T cells and APCs are stabilized by specific antigen recognition CD8 CTL janeway et al, 2005

7 T cells (CD4 and CD8) form compositionally and functionally distinct synapses CD4+, stable dsmac: actin psmac: adhesion csmac: signaling and secretion CD8+, transient

8 sequence of events leading to target cell killing by CTLs collision and non-specific adhesion re-organization of CTL architecture release of granules at site of contact janeway et al, 2005

9 APC interaction with T cell- regulates actin cytoskeleton billadeau et al, 2007

10 multiple signalling pathways are controlled by cdc42 + crosstalk

11 TCR-mediated MTOC polarization billadeau et al, 2007

12 secretory lysosomes combine features of secretory granules and lysosomes fibroblast secretory cell haematopoietic cell clark and griffiths, 2003

13 haematopoietic cells and functions janeway et al, 2005

14 related architecture of immune receptor signaling pathways in haematopoietic cells mast cell T lymphocyte Activation of downstream effectors MAPK activation integrin activation

15 intracellular distribution of rab proteins schwartz, et al. 2007

16 the rabgtpase switch regulatory signals GTP GDP GEF GDI REP GDP rab rab GTP effector targets GAP Pi other GTPases: ran, ras, rho, ARF

17 rab proteins coordinate membrane transport via effectors munro, 2005

18 characteristic features of rab GTPases

19 two mechanisms for delivery of rabs to a membrane - REP pathway for newly synthesized rab - GDI pathway for re-utilization of rab

20 synthesis route of lipid tail that is appended to C terminus of rabs

21 rab27a regulates localization and exocytosis of lysosome-related organelles in different cell types through distinct effector proteins olkkonen, 2006

22 affinity purification of rab effectors B B GSH bead GST GSH bead GSTrabGTP GSH bead GSTrabGDP A A C A D SDS-PAGE C D LC/MS-MS B A

23 isolation of munc13-4 from spleen silver stain western blot direct binding assay neeft et al, 2005

24 munc13-4 and rab27a are highly expressed in some haematopoietic cells munc13-4 rab27a actin neeft et al, 2005

25 comparison of GS2 and FHL3 granule CTL phenotypes suggests munc13-4 acts downstream of rab27a normal GS2, rab27a FHL3, munc13-4 no docking of SLs, no fusion with PM docking of SLs, no fusion with PM de saint basile et al, 2003

26 mast cell degranulation assay resting activated IgE/TNP-BSA janeway et al, 2005

27 munc13-4 is a positive regulator of mast cell degranulation hexosaminidase release (% of mock) GFP YFP-Munc13-4 wild type GFP-Munc13-4 ( ) GFP-Munc ) neeft et al, 2005

28 model for munc13-1 function in neuronal synapse synaptic vesicles pre-synaptic neuron Munc13-1 exocytosis neurotransmitter Ca 2+ releasable primed docked post-synaptic cell

29 munc13 is possibly involved in assembly of SNARE complex at synapse brose, 2007

30 munc13-4 and rab27a colocalize on secretory lysosomes YFP-munc13-4/CFP-rab27a p80 serotonin CD63 p80 YFP-munc13-4 CFP-rab27a serotonin YFP-munc13-4 CFP-rab27a CD63 YFP-munc13-4 CFP-rab27a neeft et al, 2005

31 munc13-4 localization on granules requires MHDs YFPmunc13-4 YFPmunc13-4(1-543) YFPmunc13-4( ) YFPmunc13-4( ) serotonin granule localization domain neeft et al, 2005

32 FHL3 mutant munc is mislocalized merge GFPmunc13-4 ( ) serotonin neeft et al, 2005

33 is munc13-4/rab27a complex required for secretory lysosome release? how to approach the question

34 rab27a binding site is in N-terminus of munc13-4 rab27bd neeft et al, 2005

35 munc13-4 truncations for determining rab27a-bd FL 1 C2 MHD1 MHD 2 C A B C D E G H rab27a binding maaike neeft

36 ala scan of aa in munc13-4 reveals critical region for rab27 binding maaike neeft and mark cheung

37 specific knock-down of munc13-4 in RBL-2H3 cells proteins edo elstak and parisa goodarzifard

38 rab27a binding mutants fail to rescue degranulation in mast cells beta-hexosaminidase secretion lentiviral munc13-4 construct edo elstak

39 lytic granule secretion at the immune synapse requires a complex of rab27 an munc13-4

40 has the problem be solved and can we derive a unifying model for munc13-4 and rab27a function in secretory lysosome release? rab11 Munc13-4 Granzyme B Perforin Lamp1,2 Munc13-4 rab7 rab27a rab27a rab27a mast cell compound exocytosis CTL serial exocytosis

41 interested in challenging research projects? Peter van der Sluijs;