Liao Y , Chang HC , Liang FX , Chung PJ , Wei Y , Nguyen TP , Zhou G , Talebian S , Krey LC , Deng FM , Wong TW , Chicote JU , Grifo JA , Keefe DL , Shapiro E , Lepor H , Wu XR , DeSalle R , Garcia-España A , Kim SY , Sun TT .

R01 DK110466 NIDDK NIH HHS , R01 DK039753 NIDDK NIH HHS , S10 RR024708 NCRR NIH HHS , S10 RR023704 NCRR NIH HHS , P01 DK052206 NIDDK NIH HHS , I01 BX002049 BLRD VA

	FIGURE 1:. Detection of uroplakins in nonurothelial cells. Immunofluorescence staining of paraffin sections of mouse bladder urothelium (A), as well as those of nonurothelial tissues, including the (B) renal medulla, (C) anterior prostate, (D) stomach, (E) cauda epididymis, (F) cornea, (G–K) ovary, and (L) testis. Ovary samples are from (G) wild-type mouse, (H) UPII knockout, (J) UPIIIa knockout, and (K) UPII/UPIIIa double knockout. Antibodies to individual uroplakins include (A1) Ia 4867; (A2 and L) Ib 7472; (B, C, E) 7727; (A3) II 160; (A4) IIIa 182; (D) 35804; and (F) IIIb 6177; for the description of these antibodies, see Table 1 and Supplemental Table S1). Other antibodies include alpha-tubulin (α-Tub), K8, V-ATPase, and H+,K+-ATPase, as noted. (M) Detection of uroplakins mRNAs by RT-PCR in bladder (lane 1; B), testis (2; T), ovary (3; O), or water control after 30 (low, L) or 35 (high, H) cycles Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) control. Note the detection of uroplakins in B the apical surface of the K8-positive renal collecting duct, (C) the upper parts of some of the K8-positive secretory prostatic epithelial cells, (D) the H+,K+-ATPase-positive gastric parietal cells, (E) the apical surface of the V-ATPase-negative epididymal epithelial cells, (F) the corneal epithelium, (G–K) oocytes, and (L) spermatids in testis. Also note in G to K the absence of UPII (and its partner UPIa) and UPIIIa in the UPII- and UPIIIa-KO oocytes, respectively, thus confirming the specificity of the uroplakin staining. L = lumen. Nuclear staining: DAPI (A–F) or To-Pro-3 (G–K). Bars equal to 10 µm (A, C, F, and L), 50 µm (B, E), 20 µm (D), or 30 µm (G–J).
	FIGURE 2:. Colocalization of uroplakins with CD9 and CD81 in polarizing mouse oocytes. (A–E) immunofluorescence staining of immature oocytes (A1–E1) and mature eggs (A2–E2) using (A) anti-CD9, (B) Cholera toxin (CTB, recognizing ganglioside GM1, a raft marker); (C, D) anti-uroplakin IIIa (35804); and (E) LCA). The staining was performed using intact oocytes and eggs (A, B, C), Triton X-100–treated samples (E), or paraffin sections (D*). Note the relatively even surface-association of uroplakins and other surface markers in immature oocytes (A1–E1), and their polarization to the microvilli-rich pole on egg maturation (A2–E2). Also note the abundant cytoplasmic UP vesicles in permeabilized oocytes (D1), and their predominant polarized surface-association in mature eggs (C2, D2). (F–M) Oocytes were double-stained using antibodies to (F) UPIb (AU-Ib-2)/Sec23A (ER marker); (G) UPIb (AU-Ib-2)/GM130 (Golgi); (H) UPIb (7472)/LAMP1 (late endosome); (J) ovastacin/LCA (both cortical granule markers; note precise colocalization); (K) UPIIIa (35804)/LCA; (L) Hsp90/Alix (both multivesicular body markers); (M) UPIb (7472)/Alix. Note in M the partial colocalization of UPIb with Alix. Bars equal to 10 µm (A-E) or 5 µm (F–M).
	FIGURE 3:. Uroplakin association with cell-surface, multivesicular bodies, and exosomes of mouse oocytes. (A, B) Colocalization of uroplakins with (A) CD9 and (B) CD81 at egg plasma membranes (zona pellucida free). (C, D) Colocalization of UPII (S3045), CD9, CD81 by IF-staining of intact eggs with intact zona pellucida viewed at (C) low or (D) high magnification. Note that in A and B the precise and partial colocalization of UP with CD9 and CD81, respectively; in D the partial colocalization of UPII and CD9 on the exosomes in the PVS (yellow arrows) and the colocalization of UPII and CD81 on some exosomes in ZP (white arrows). Blue nuclear staining by Hoechst 33258 in C and D. (E–J) IEM localization by staining ultrathin sections of oocytes (E, G, H) or eggs (F, I, J) using antibodies to UPIa (E, G, I) and Ib (F, H) and ovastacin of cortical granules (J). Note the association of UP’s with oocyte surface (E), egg microvilli (F), multivesicular bodies (G, H1) and their intraluminal vesicles (H2; asterisks), and exosomes (I). Note the distinct staining patterns of the uroplakin-positive MVBs (G, H1) and cortical granules (J; asterisks). (K) Transmission electron microscopy of an egg from a UPII-knockout mouse showing unusual multilobular bodies (**) possibly representing autophagasomes. Uroplakin antibodies: (A, E, and I, Ia128; B, C, and D, II S3045; and F and H, Ib 7727). Bars equal to 2 µm (A, B, D, and K), 10 µm (C), 0.5 µm (E-G, H1, I and J), or 0.2 µm (H2).
	FIGURE 4:. Fertilization of Xenopus laevis (Xl) eggs led to tyrosine phosphorylation of UPIIIa and Src. Xenopus oocytes (A–I) were stained using (A) normal IgG (negative control), or antibodies to (B) Xenopus UPIa or xUPIa (19228), (C) xUPII (13641), (D) xUPIb (13638), (E) xIIIa (19230), (F) xIIIb (4865), (G) xIIIa-Y249 (nonphosphorylated peptide, 35761), (H) xIIIa-Y249P (Tyr-phosphorylated peptide, 35760), or (I) Src-Y416 (Tyr-phosphorylated peptide). Alpha-tubulin was colocalized in A–F as a control. Note the detection of all five Xenopus homologues of mammalian uroplakins on the egg surface. (J–L) Xenopus eggs were stained using antibodies to (J) xIIIa-Y249, (K) normal mouse IgG, or (L) normal rabbit IgG. (M–ZZ) immunofluorescence staining was done using (M–O) control Xenopus eggs, (P–R) sperm-fertilized eggs, (S–U) eggs pretreated with an antibody to xUPIIIa before sperm fertilization, (V–X) hydrogen peroxide-activated eggs, and (Y–ZZ) SKI-606–pretreated eggs before hydrogen peroxide activation. In this series of experiments, each type of egg was stained using antibodies to xIIIa Y249P (first column), Src-Y416P (second), and pan phosphorylated-tyrosine (third). Note the increased Y-phosphorylation of xIIIa and Src in both sperm-fertilized (P, Q) and peroxide-activated (V, W) eggs and the blockage of this reaction by an anti-xUPIIIa antibody (S, T) and Src inhibitor SKI-606 (Y, Z). Bars equal to 20 µm.
	FIGURE 5:. Parthenogenetic activation of mouse eggs led to the tyrosine-phosphorylation of UPIIIa and Fyn. Permeabilized normal eggs (control; first column), ethanol-activated eggs (second column), and SU6656 (Fyn inhibitor)-pretreated and ethanol-activated eggs (third column) were stained using antibodies to (A–C) UPIIIa-Y266 (35759), (D–F) UPIIIa-Y266P (35758) (synthetic peptide containing the phosphorylated (P)-Tyr 266), (G–I) Fyn, (J–L) Fyn-Y418P (synthetic peptide containing the phosphorylated Tyr 418 of Fyn, and (M–O) phosphorylated Tyr. Note in the second column that ethanol-activation led to the Tyr-phosphorylation of UPIIIa-Y266 (E) and Fyn-Y418 (K), and their blockage by SU6656 (third column). (P–R) Immunostaining of intact mouse eggs with antibodies to (P) UPII (S3045)/Fyn/CD9, (Q) UPIIIa-Y266P/Fyn-Y418P, and (R) UPIa/GM1-CTB (a raft marker). Note that in P the substantial colocalization of UPII/Fyn with CD9; in Q the colocalization of tyrosine-phosphorylated UPIIIa and tyrosine-phosphorylated Fyn; and in R the poor colocalization between UPIa (AU-Ia-1) and the raft marker GM-1. Bars equal to 10 µm (A–O) or 5 µm (P–R).
	FIGURE 6:. Association of uroplakins with the mouse sperm head. (A, B) Paraffin-sections of mouse testis were triple-stained using antibodies to uroplakins Ia (4867) or II (160) (green), alpha-tubulin (red) and To-Pro-3 (blue; nuclei). (C–E) Uroplakin staining of intact mouse sperms from (C) wild-type, (D) UPII-knockout, and (E) UPIIIa-knockout mouse using antibodies to specific uroplakins as noted. (F, G) Staining of mouse sperms that have been treated with (F) PBS or (G) 0.1% Triton X-100. (H, I) UPIIIa staining of a control sperm (H) or a capacitated sperm (I). (J, K) Triple staining of control sperms (J) or those pretreated with 0.1% Triton X-100 (K), using antibodies to UPIIIa, Sp56 (acrosome marker) and DAPI. (L, M) Double-staining of sperms (that have been heat-treated) using anti-UPIIIa and PSA. Antibodies to uroplakins are as follows: Ia, AU-Ia-1; II, S3045; Ib, AU-Ib-2; IIIa, 35804; IIIb, 6177 (Table 1 and Supplemental Table S1). Note in H, I, J, and K the UP-staining of the sperm heads, in D the absence of UPII and its partner Ia in the UPII-null sperms, and in E the absence of UPIIIa in the IIIa-KO sperms. Also note in L that heat treatment had little effects on hook-associated UP-staining, and led to the formation of abnormal PSA stained swelling near the transitional zone between the mid-body and tail. The sperms were collected from cauda epididymis, and nuclear staining was by DAPI. Bars equal to 10 µm (A, B), 5 µm (F, G, L, and M), or 2 µm (C–E, H–K).
	FIGURE 7:. Effects of uroplakin knockout on mouse gamete fertilization. (A–C) Uroplakin-deficient eggs had a reduced fertilization rate. IVF assays using (A) uroplakin knockout eggs and sperms, (B) uroplakin knockout eggs and WT sperms, and (C) WT eggs and uroplakin knockout sperms. Note in A that uroplakin deficiency impaired the fertilization (2-Cell; blue bars) but not embryonic development (Blastocyst, BL; red bars), and in B and C that this impairment was caused by UP deficiency in eggs. Eggs and sperms were collected from 8 to 10 female and two to three male mice for each group, respectively. (D) Effects of anti-uroplakin antibodies on the in vitro fertilization of the mouse eggs; 5 WT female mice were used for each group. The antibodies used are affinity-purified rabbit antibodies to the extracellular domains of mouse UPIa (128) and UPIb (7727), and to a mouse UPIIIa synthetic peptide corresponding to a juxta-membrane epitope (position 179–191 QTLWSDPIWTNRP(C)). The ZP-intact WT eggs were preincubated with these antibodies (final concentration 200 µg/ml) for 30 min prior to incubation with WT sperms. Error bars are the SD of four independent groups. Asterisks mark values that are significantly different from the controls (p <0.01, one-way analysis of variance [ANOVA]). (E) In vivo pup production: The litter sizes of various breeding combinations between the WT and double-UP-knockout mice. Note that pairs involving only female, but not male, KO mice had a reduced litter size. Five breeding pairs (8–12 wk old) were used for each group, and four to five litters were produced from each pair. Error bars are the SD of five independent groups. Asterisks denote statistical significance (p <0.01, one-way ANOVA).
	FIGURE 8:. Mammal-specific amino acid residues and motifs in uroplakins. (A) Examples of mammal-specific residues (yellow) and amino acid residues that are shared by ALL uroplakins (“all-uroplakin-residues or AUR; red) from UPIa, Ib, II, IIIa, and IIIb of ∼20 mammals (17 placental and three nonplacental) and 10 nonmammals (Desalle et al., 2014). Mammal-specific residues are defined as those that are present in >90% of mammals and <30% of nonmammals. The horizontal green line demarcates the sequences of the mammals (above) and nonmammal vertebrates. (B) The overall location of mammal-specific motifs (MSM; red box; greater than three consecutive residues, five with a single interruption, or six with two interruptions) in uroplakins as indicated. TMD (transmembrane domain). (C) Model depicting the evolution of all the known uroplakin genes. Symbols: red arrows (genealogical relationship), two-headed black arrows (protein–protein interaction), asterisk (a strong pattern of significant skew towards dN/dS>1.0 suggesting possible selection that accompanies the duplication events that produced the paralogue group) (Desalle et al., 2014), phosphotyrosine phosphatase receptor (PTPR) (Chicote et al., 2017), tetraspanin precursor (TM4), million years (MY). See main text for details.
	FIGURE 9:. Schematic diagrams showing the distinct patterns of uroplakin trafficking in (A) mouse oocyte/egg and (B) a terminally differentiated umbrella cells of mammalian bladder urothelium. (A) In mouse egg, uroplakins (red triangle luminal domain with a cytoplasmic tail; existing possibly as heterotetramers; see Discussion) are delivered to the cell surface via exocytosis or to exosomes via MVBs. (B) In urothelial umbrella cells, uroplakins are assembled in trans-Golgi network into 16-nm particles (red circles; 16-nm particles), which form growing two-dimensional crystals delivered via DV and FV to the urothelial apical surface, where they form the characteristic urothelial plaques (Wankel et al., 2016). Some of the apical surface-associated uroplakins can be endocytosed into multivesicular vesicles for lysosomal degradation (Vieira et al., 2014). Other abbreviations: EE (early endosome) and TGN (trans-Golgi network). Thickness of the arrows approximates the relative abundance of the pathways in the two cell types.

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